US2410857A - Apparatus for forming materials - Google Patents

Description

NW, 12, 1946. w. B. AHERN Q APPARATUS FOR FORMING MATERIALS Filed Dec. so, 1945 INVENTOR.

Patented Nov. 12, 1946 APPARATUS FOR FORMING MATERIALS William B. Ahern, De Kalb, 111., assignor to The Rudolph Wurlitzer Company, Chicagm'IlL, a

corporation Application December 30, 1943, Serial No. 516,316

This invention relates to an apparatus for moulding plastics, paper, wood, cloth and the like, and particularly that type of material which may be moulded and formed with the application of heat and pressure. It is particularly applicable to forming molded tips to the desired shape or form under pressure coupled with" heat transfor treatment.

The invention primarily contemplates the application to the material of a male forming-plug of compressible resilient material such as may comprise an adherent fluid mass, said plug substantially conforming to the general shapeof the for-med material, and likewise, to a female form of light sheet heat transfer metal. In the use of such a plug the invention also contemplates the application of equalized fluid pressure to both the fluid mass of the plug and the thin heat transfer metal form. Such equalized fluid pressure is adapted to sustain the thin metal female form andso compress the resilient male form or plug as to cause it to transmit such pressure for compressing the material transversely thereof in different directions. Such a plug may be of soft rubber such as to be fluid-like in its transmission of pressure while maintaining its adhering mass and shape formation.

The apparatus comprising this invention has the advantage of rapid assembly of the forms within their pressure chambers so as to permit the formed material to be conveniently changed, while at the same time having the advantages of rapid heat transfer through a thin sheet female form, light in weight and inexpensive, to provide for different sizes and shapes.

The full nature of the invention will be understood from the accompanying drawing and the following description and claims: I

Fig. 1 illustrates one form and application of the'invention showing the apparatus in central vertical section with parts in elevation.

Fig. 2 illustrates a second or modified-form of the invention showing the apparatus in central vertical section with portions thereof in elevation.

Referring to Fig. 1, there is illustrated a stationary fixed platen orsupport Ill and-a movable platen or head i l which may be clamped in operating position and secured by the threadedtie rods and nuts 12. i Carried by the support ['0' there is a cradle l3, open at the top to provide a pressure chamber ld'and support for the female or contour form 15.

4 Claims. (01. 18-19) sufficient inherent strength and rigidity to retain its form and support the material to be formed. It need not be of such thickness and strength as to withstand the pressure to be applied in the forming operation. Such a contour form has the advantage of being conveniently and easily formed to the desired contour as well as rapidly transmitting heat from the chamber M to the material to be formed. The contour form I5 is flanged with a peripheral cupped portion indicated at I6'for providing a support therefor in the cradle capable of being sealed thereabout by the gasket l1. Mounted in sealed position, it 'is removably secured by the screws l8. Y

The head ll carries a chamber cover l9 coextensive with the cradle l3 to which a flexible blanket 2| is secured and sealed about its edges by'the clamping ring or members 22. Said blanket is arranged to overlie and press against a forming plug 20. Said plug comprises an adherent fluid mass such 'as .rubber or similar compressibleresilient material and substantially con- Thus said plug serves as a male forming die, but with sufiicient fluidity to transmit pressure in all directions. s

engaging the flange of the contour form. Thus the corrugated surface provides a series of ducts 24 providing atmospheric connection with the initial space betweengthe plug and work and between the work and form. Thejmaterial to be formed is disposed over or within the contour form and compressed therein by the plug, the material being indicated at 25.

The forming pressure such as to highly compress the material under application of heat, is generated in the pressure chamber I4 by steam introduced'through the steam pipe 26 communieating with the steam delivery pipe 21 controlled by the steam valve 28 which is in communication with a water inlet pipe 29 controlled by the valve 30. The fluid pressure thus created in the chamber is transmitted to the pressure chamber 3] provided between the chamber cover l9 and V the blanket 2i. Thus the pressure exerted on both sides of the thin metal contour form is equalized so as not to distort it. For this purpose the chamber l4 is'in communication with 32 directly to the chamber 3|. For draining the chamber I4 of condensation, there is provided a drain pipe 35 communicating with thebottom thereof.

In operation the sheet material 25 to be formed may be placed over or within the contour form either preformed or otherwise, whereupon the plug 20 is inserted and the head II lowered. This has the effect of generally conforming the material to the form. When the head has been pressed down to its operating position as illustrated, it is clamped and tightened so that the blanket rests upon the breather plate 23. When desired, the tank 34 will have been filled with the proper liquid. Steam is then admitted to the chamber I4 under pressure, at the same time transmitting said pressure to the liquid in the tank 34. This equalized fluid pressure is thereby exerted equally against the plug 20 and the contour form I5. After the pressure is increased, the resilience or fluidity of the mass in the forming plug causes it .to in turn transmit the fluid pressure against :the material transversely thereof, whereby said material is compressed under high pressure equally throughout its entire surface and to the contour of the form. At the same time heat carried by the steam in the chamber I4 is rapidly transmitted through the thin metal wall of the form directly to the material. This has the effect of causing the material 25 to be set in its formed and compressed condition. Similarly, wherein the material is of such a character as to be set and formed by cooling, it may be rapidly cooled through the heat transfer of the thin walled form by discharging cooling liquids, such as water, through the pipe 23. Also, the material first may be heat treated by the injection of steam into the chamber followed by the injection of a cooling fluid while maintained in its compressedstate through the pressure transmitted thereby.

In Fig. 2 the contour form I5 is mounted within .an auto-clave comprising a pressure cylinder II3 for providing a pressure chamber I IA. The form I5 is carried through its outwardly extending flanges upon a series of clamps II5 seated upon suitable platforms I I6 mounted upon the cylinder. The plug is pressed into the form With the material to be formed extending therebetween. The blanket 2| extends over the plug and is clamped about its edges in sealing engagement with the flange of the form by the clamping ring or members I22. Said clamping and sealing action isprovided by the turn screws carried by the clamps. II5. A suitable corrugated or apertured breather plate I23 is mounted between the blanket and form to permit entrapped gas to be withdrawn from between the plug and form by the vacuum line I24, or otherwise permitted to escape. In fact, the form and plug with the material therein is assembledand the clamps applied outside of the cylinder whereupon the assembled arrangement is mounted on the platforms H6; The assembly also carries a water ring I25 wherein it may be desired to protect the blanket 2I from the deleterious effects of steam.

and the cylinder closed, the fluid pressure in the pressure chamber I I I may be built up by directing steam therein through the pipe I26 from the steam pipe I21 controlled by the valve I28. Water may similarly be admitted from the water pipe I29 controlled by the valve I38. The cylinder may be drained by the drain pipe I35.

Theactionis similar to that above described wherein the pressure exerted in the chamber H4 is actually applied about the form and over the plug. When water is placed in the Water ring I25, the steam pressure will be transmitted through such liquid in the manner above described, aswell as wherein the water ring may contain other liquids such as glycerine or oil. Thus the liquid contained in the ring I25 will I protect the material and blanket, such as rubber,

from excessive heat during the steam application.

The invention claimed is: 1. Apparatus for forming material involving the application of pressure and heat exchange including a female contour form of thin metal for ;rapid heat transmission, means for supporting said form within a pressure chamber, a complementary male form comprising a plug of compressible resilient material, a flexible and resilient blanket associated with and extending over said plug, means cooperating with said resilient blanket to form a chamber for retaining a pressure transmitting liquid medium thereover for protection thereof, and a source of fluid heat exchange and pressure medium communicating with both said pressure chambers for applying equalized pressure on said liquid medium and female form for compressing said material and causing rapid heat exchange therewith through the thin metal of the female form.

- 2. Apparatus for forming material involving the application of pressure and heat exchange including a female contour form of thin metal plementary male form comprising a plug of compressible resilient material, a flexible and resilient blanket associated with and extending over said plug, means cooperating with said resilient blanket to form a chamber for retaining a pressure transmitting liquid medium thereover for protection thereof, a source of fluid heat exchange and pressure medium communicating with both said pressure chambers for applying equalized pressure on said liquid medium and female form for compressingsaid material and causing rapid heat exchange therewith through the thin metal of thefemale form, and an apertured breather plate. interposed between said blanket and the periphery of said female form to permit entrapped gas to escape therethrough.

3. Apparatus for forming material involving the application of pressure and heat exchange, including a female contour form of thin metal for rapidheat transmission, a cradle within which said form is supported and sealed to enclose a pressure chamber, a complementary male form extending into said female form with said material therebetween, said male form comprising a plug of compressible resilient material, a flexible and resilient blanket associated with said plug, a chamber cover sealed over said blanket to provide a pressure chamber therebetween, means for securing said chamber cover over said cradle with said forms in material engaging relation, a source of'liquid pressure medium communicat- When the assembly is placed in the cyl nder 'ing with the last mentioned pressure chamber to including a female contour form of thin metal for rapid heat transmission, a complementary male form extending into said female form with said material therebetween, said male form comprising a plug of compressible resilient material, a flexible and resilient blanket associated with said plug, clamping means for sealing said plug between said blanket and female form, a closed pressure tank for supporting said forms therein and providing a surrounding pressure chamber, means for introducing a heat exchange and pressure medium into said pressure tank for exerting equalized pressure on said forms to compress the material therebetween, and a liquid containing ring surrounding said blanket for providing a bath of protective liquid thereover to prevent direct contact therewith of the said pressure medium.

WILLIAM B. AHERN.

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