US2966183A

US2966183A - Press platen actuating means

Info

Publication number: US2966183A
Application number: US726182A
Authority: US
Inventors: Herbert J Werner
Original assignee: Baldwin Lima Hamilton Corp
Current assignee: Baldwin Lima Hamilton Corp
Priority date: 1958-04-03
Filing date: 1958-04-03
Publication date: 1960-12-27
Anticipated expiration: 1977-12-27

Description

Dec. 27, 1960 H. J. WERNER PRESS PLATEN ACTUATING MEANS 4 Sheets-Sheet 1 Filed April 3, 1958 INVENTOR. HERBERT J. WERNER ATTORNEYS Dec. 27, 1960 H. J. WERNER 2,966,183

PRESS PLATEN ACTUATING MEANS Filed April 3, 1958 4 Sheets-$heet 2 INV EN TOR.

' HERBERT J.WERNER F155- @@9@ ATTORNEYS Dec. 27, 1960 H. J. WERNER PRESS PLATEN ACTUATING MEANS 4 Sheets-Sheet 3 Filed April 3, 1958 INVENTOR. HE RBERT J. WER NEE "HQ T IL ATTORNEYS Dec. 27, 1960 H. J. WERNER 2,965,183

PRES-SPLATENACTUATING MEANS Filed April 3, 1958 4 Sheets-Sheet 4 INVENTOR. HERBERT J. WERNER QMQK A1 TORNEY$ United States Patent PRESS PLATEN ACTUATING MEANS Herbert J. Werner, Hamilton, Ohio, assignor to Baldwin- Lima-Hamilton Corporation, Hamilton, Ohio, a corporation of Pennsylvania Filed Apr. 3, 1958, Ser. No. 726,182

3 Claims. (Cl. 144-281) This invention relates to an apparatus for closing the platens of a steam press or the like when used for the manufacture of sheet material such as chipboard, plywood and the like.

At the present time it is usual to manufacture sheet material such as chipboard or hardboard from properly prepared wood fragments by consolidating the fragments and a suitable binder under high pressure between the heated platens of a press. A large number of sheets are formed at each closing of the press, and for this purpose a large number of pan-like dies are provided which are filled with the wood fragment-binder mixture and slid into place between movable pressed platens. As the slide of the press is closed (usually in an upward direction) it closes first the lowermost die space, then the second, third, and so on until the platens are in a compact pile with the material holding dies therebetween. Continued heat and pressure is applied to the stack for a predetermined interval of time sufficient to complete the proper reaction of the binder material.

In the usual multiple platen press, the speed of closing is made as high as possible to reduce the cycle time and to increase production. If the speed of closing is made too high the loose Wood fragments are blown out from between the platens by the escaping air. Various expedients have heretofore been proposed to prevent such blowing of the material, but they have not been entirely satisfactory.

The present invention has for its primary object to provide an improved means to connect the platens of a multiple platen steam press or the like in such a manner that the overall closure time is very short, yet the closing movement of any single platen is at a very slow rate so that the closure of the press is accomplished rapidly and without blowing material out from between the platens or otherwise disturbing it.

Another object of the invention is to provide improved means for controlling the movement of the platens of a multiple platen steam press or the like which is easy to construct and maintain and which functions efi'iciently and eifectively to prevent displacement of material from between the platens upon closing.

Another object of the invention is to provide a means which will function to permit the press to be closed without damage if several of the platen spaces have been left unloaded by the operator either intentionally or through an oversight.

Other objects and advantages of the invention will become apparent from the following description of a preferred form thereof, reference being had to the accompanying drawings, in which Figure 1 is a diagrammatic front elevational view of a press embodying the present invention;

Fig. 2 is a side elevation thereof;

Pig. 3 is a section on line 3-3 of Fig. 2; and

Figs. 4 and 5 are diagrammatic representations of the platen stacks when closed, Fig. 4 showing the conditions existing when certain of the platen spaces have been left vacant and Fig. 5 showing the conditions when all of the platen spaces are properly loaded.

The present invention is shown in the drawings as embodied in a conventional steam press the platens of which are hydraulically moved. The pistons and cylinders and the associated control mechanisms are either diagrammatically disclosed or are completely omitted for the sake of clarity. The invention comprises, in combination with the press platens, means to associate each platen with its neighbor above and below in such a manner that a closing movement applied to the lowermost platen is communicated to all of the platens by linkage mechanism resembling a lazy tong fixed at one end to a movable slide of the press and at its opposite end to the stationary press crown. The pivot members for the lazy tong links are extended to support the press platens. Thus, as the press slide is closed the lazy tong support is closed with the result that each pivot point and the die or platen supported thereby is moved in an upward, or the same direction, at varying rates. For example, if there are twenty platens supported by the lazy tong mechanism, and a closing motion at the rate of 100 per minute is imparted to the lowermost platen, the platen immediately above it moves upwardly at the rate of 95" per minute, the next succeeding platen at per minute and so on. The actual closing movement then, of each platen against the one immediately above it is only 5" per minute. At this very slow closing rate thus available there is no danger of displacing the wood fragments from between the platens.

In the diagrammatically disclosed press in the drawings, 1t) designates the bed of the press and 12 designates the press crown which is supported over the press bed by spaced columns 14 and tied thereto by the usual corner tie rods 16. In the present instance there are three columns 14 at the front and back of the press.

A movable lower slide 18 extends from front to back of the press and is supported for guided movements with respect to the center of the columns 14 of the press at both the front and back and is actuated by appropriate power cylinders 19 carried in the bed 10. As is well known in the art, certain of the power cylinders are used for rapid closing of the platens and others for the final pressure applied to the stack of platens. In the press shown, outer and larger power cylinders 20 are used to impart a final pressing pressure to the platens through a stool 21 which extends from side to side of the press over the slide 18. The stool may be guided on the outer of the columns if desired. The smaller power cylinders 19 may be used to move the platens rapidly together through the mechanism hereinafter described.

Die supporting platens 22 are carried between the stool 21 and the crown of the press and are shown in Figs. 1 and 2 in their open position. Each of these platens is adapted to receive a pan-like die which is filled outside 7 links.

the press with an appropriate material such as a mixture of wood fragments and binder. Once the pan-like die has been filled it is placed over one of the platens 22 and the loading is repeated until all of the die spaces have been filled and the press is then ready for closure.

In the usual construction the platens are supported in their open position by gap ladders which comprise a spaced pair of staggered shelf-like stop members which successively engage extensions from each of the platens as the lower slide is moved away from the crown in an opening movement. Such spacing devices can be dispensed with in the case of the .present invention or they can be utilized, if desired for additional supportof the platens in the. open position of the press.

'Fixed to thelower slide 18 is one end of a lazy tong mechanism comprising pivoted links24 which are attached to a bracket 26 in a pivotal connection 28. The links 24 those pivot points which occur at the centers ofthe Each pivot point includes a pin which extends inwardly towards the center of the press and is sufliciently heavy that it will easily support one of the press platens v and the load intended to be carried thereby.

The lazy tong mechanism is, of course, duplicated on the front and back of the press. If the mechanism occupies a substantial length when open it can be supported against movement away from the plane of operation intermediate its ends by one or more brackets 32 fixed to a stationary column of the press. Each bracket comprises wings which extend outwardly from the supporting column sufliciently to encompass the path of movement of outwardlyextending pins which are a part of the central pivot points B between at least two pairs of On the'inner face of each wing, each bracket is provided with a channel or groove 34 into which the pivot pins are extended and since'the movement of these central pivot points is linear, each channel 34 can extend vertically from top to bottom of the bracket wing. The bracket wings may be relieved at those points which might interfere with the free movement of. any of the other pivots for the links. a

7 While the projecting pins at. the pivot points A and B may be used to support the press platens, additional platens may be supported intermediate the ends of the 'links and for this purpose inwardly projecting pins C are carried by the links of the lazy tong mechanism. Since these pins, and the end pivot points A have a lateral component of motion as thepress is closed, the platens supported thereby are provided with pin receiving grooves 36 formed either in the under surface of the platens themselves or in wings extending therefrom but which accommodate the lateral relative movement between the sillpporting pins and the adjacent under surface of the p aten. movement ofrthe platens may be employed if desired.

In operation, assuming the press to be in the open position shown in Fig. 1, the operator loads appropriate dies with the material to be consolidated and places them from its supporting pins.

Additional guiding means to assure a vertical over the press platens 22. .The press closing cylinders are then actuated and the lower slide 18 and the'stool 21 begin to rise. At the same time the lazy tong links,

.the lower end of the mechanism being fixed to the slide 18, begin to close so that each of the platens ad- 'vances towards a retreating platen above it except, of -course, for the uppermost one of the series which advances against a die fixed to the stationary crown 12.

number of platens in the series to give the relative closing rate for any one of the platens. The closing rate of each of the platens is equal. Thus, if the rate of closing of the lower slide 18 is per minute and there are twenty die spaces closed simultaneously, the rate of closing of each die space is 5" per minute. Once the platens have been brought to the die closing position with the assistance of the lazy tong mechanism, the final pressing of the compound is done by the stool 21 and its larger power cylinders 20. Each of the platens is free to leave its supporting pins during the final pressing operation, there being no fixed pivotal or other connection between these supporting pins and the platens themselves. At this time stool 21 is free to separate from slide 18 so that the final pressure, which is quite high, is not taken by the platen supporting pins, ,but is transmitted directly from one platen in the stack to the next. It will thus be seen that the movement of the slide 18 can be very fast without causing any blowing of the material out from between the platens since the relative movement of each of them with respect to its neighbor above and below is slow.

The present invention is also of'great advantage in the manufacture of plywood and other materials where it is necessary to open and close the press platens repeatedly to allow for the escape of steam that is formed during the curing cycle. With many of the present presses, and all of the commonsuccessively closed stack types, it is necessary to open the press completely before the last of the die spaces opens. This is a time consuming operation that is avoided by the present invention in which the die spaces open uniformly as soon as the slide 18 and the stool 21 start to descend.

Figure 5 of. the drawings shows the position of the platens 22 when all of the die. spaces between the platens are loaded and under the pressure of the stool 21. In the interests of clarity only a portion of the length of each platen and die has been shown and the die spaces are represented by cross-hatching, In the usual condition of operation all of the die spaces are filled and there is very little movement of any of the platens away On occasion, however, the operator either intentionally or accidentallyniay leave one or more of the die spaces empty so that a platen would be forced to close directly against its neighbor without intervening die or material. No spacers are used between the platens of the present press so that the final closing pressure is transmittedrover the entire area of a platen.

The condition of the platens with unfilled spaces is shown in Fig. 4. It will there be seen that the die supporting platens have been carried upwardly from their engagement with the pivot pins of the lazy tong mechanismby the continued movement of the stool 21. Thus the platens have been brought to a very closely adjacent position by the movement of the lazy tong mechanism and its actuating slide 18 but have been closedfinally by the continued movement of the stool 21..

What I claim is:

1. In a multiple platen press mechanism comprising a movable slide, a stationary press crown, a plurality of die receiving platens interposed betweensaidmovable slide and said stationary press crown, means connected to saidslide for exerting initial pressure to move the platens into, contact with, each other, said means mcluding a lazy tong linkage having one endfixed to sald slide and its opposite end fixed to said crown, means on the lazy tong linkage to support individually said plurality of said die receiving platens, said supporting means comprising projections on said lazy tong linkage extending inwardly under said platens but otherwise unconnected thereto, and means to exert a final pressing pressure upon the underside of said platens whereby when said platens are moved toward the stationary press crown by said means for;exerting pressure on theunder side of the platens, said platens are free to move 01f said supports on said lazy tong linkage.

2. The structure according to claim 1 in which the projections on the lazy tong linkage for supporting the plurality of die receiving platens are positioned at the 5 pivot point between the several link members making up the lazy tong linkage.

3. The structure according to claim 1 in which the supporting means for the plurality of die receiving platens is intermediate the pivot points of the link members 10 making up the lazy tong linkage.

References Cited in the file of this patent UNITED STATES PATENTS Locher Dec. 12, 1933 Stanley et a1. Sept. 5, 1939 Perony Apr. 16, 1940 Moore Feb. 19, 1952 Uschmann May 21, 1957 Thurnher Apr. 28, 1959 FOREIGN PATENTS Great Britain Oct. 28, 1936