US2385352A - Method of making hollow panels - Google Patents

Description

Sept. 25, 1945. Q Q DAVls 2,385,352

METHOD OF MAKING HOLLOW PANELS Filed June i2, 1942 INVENTOR OA/VfPCLABE/VftDAV/j BY MM .2? m

ATTORNEY l atented Sept. 25, 1945 METHOD OF MAKING HOLLOW PANELS Oliver Clarence Davis, Louisville, Ky., assignor to The Mengel Company, Louisville, Ky., a corporation of New Jersey Application June 12, 1942, Serial No. 446,817

7 Claims.

This invention relates to methods and apparatus for making structural units such as doors, walls, partitions, or the like, and, inasmuch as the invention may be utilized to great advantage in the making of doors, it will be illustrated and soft grid, a d for retaining the Said facing described specifically with reference to such hers fiat during e glue Setting Operationstructural units. For a better understanding of the invention,

In recent years, the demand for a door that reference s made to the accompanying d w n is light in weight, thermal insulating, fire-resist in Which! ant, inexpensive to manufacture, structurally Figure 1 is a perspective View Of a (1001 made stable upon exposure to air of varying humidity, in accordance with the teachings of this i venand workable and strong at its edge portions for ti w parts k n w y for cleerness of receiving conventional hardware such as latches, illustration; door knobs, hinges, etc., has greatly increased. Figure 2 is a perspective v w on a n ar d Many structural arrangements have b e advoiii scale of the grid or filler of the door with one cated, but the method of making the same has of the ribs broken away to show the ventilating become a very important consideration. Slots One very satisfactory structural arrangement Figure 3 is an enlarged View Of & D f for a door contemplates the use of a grid or filler 0118 Of the ribs 0 t d illustrate e of relatively soft material surrounded by a framew Clearly the Ventilating 510155 work of relatively firm material constituting the Figure 4 is a Side elevation f a multiple rails or edge portions of the door, with facing plate press havin a. plurality of the aforesaid members of wood Veneer or lywood panels, structural units lodged therein for processing;

Such a door is shownin United States Letters Figure 5 is an enlarged View, p y in Section, Patent No. 2,173,808, issued September 19, 1939, W of the combination a ve nd connectinap u to G. D. Kellogg. employed to place pressure within the structural In producing doors of this ty it i i bl assembly, and illustrating the pressure valve to employ a lightweight thermal-insulating maclosed; terial for making the grid or filler of the core, Figure 6 is an enlarged view, pa y in section. such as fibre board of the kind frequently used 0f the combination valve and connecting plug, for thermal insulation and weighing, for instance, illustrating the pressure valve open, and the con- 8 to 14 pounds to the cubic foot, and to employ nesting plug sealed in the aperture I5 of the a hot-setting glue for securing, in a short period aforesaid structural assembly. of time, the facing members to the grid and While I have shown a fabricated or built-up framework assembly. grid for the door, it is to be understood thata To obtain a satisfactory bond between the facmachined or molded grid, similar to that shown ing members, grid and framework, the aforesaid in Figures 3 and 4 of the aforesaid patent to parts are preferably assembled in a hot-plate G. D. Kellogg, may be substituted without depress, and subjected to relatively high pressures parting from the spirit of the invention. Simiand temperatures for a time suficient to set the larly, while I have omitted the incombustible lue. sheets of asbestos placed between the grid and However, the pressure required to assemble facing members, it is to be understood that these such structural units often injures the soft grid may be used without departing from the spirit or filler, and produces a door having objectionof my invention. able waves or similar imperfections on the outer With reference to Figure 1, it will be observed surface of the facing members thereof. that the structural unit is illustrated in the form Therefore, the primary object of the present of a door having a grid, or lattice-work filler l6 invention is to provide a method of making such of relatively soft material, a framework comprisdoors that will not only eliminate entirely the ing rails 24 and stiles 26 of relatively hard ma aforesaid objections, but'greatly increase producterial, and facing members [2, which members tion efiiciency. preferably consist of composite piles of wood ve- Briefiy, the method disclosed in the present neer, the grain of one ply 22 being arranged crossinvention comprises assembling the grid, framewise with respect to the grain of the ply 2!. work, and facing members with a suitable glue or The grid 16 preferably consists of two series of other adhesive interposed between the parts; ap-

plying external heat and pressure to the parts to bond the same together; and simultaneously therewith applying pressure internally of the said assembly to prevent collapsing or injury to the intercrossed strips [6a of fibrous or other relatively soft material, in which the strips in a given series extend substantially parallel to each other and at an angle to the strips in the other of the said series. The strips of each series are preferably notched at I6b, as illustrated in Figures 2 and 3, so that the strips interlock at the cross-over points between the strips of the two series. Figure 1 clearly illustrates this. arrangement, and the enlarged detail of the grid I6 shown in Figure '2 clearly shows the interlocked relation of the strips at the crossover points. It is also to be understood that the notches Ifib may be alternately arranged along the opposite edges of the strips IBa, so that the grid will become an inseparable, interlocked-assembly, when the facing members are secured thereto.

With further reference to Figures 1 and 2, it will be apparent that the interlocked strips Ilia of the grid I6 form a plurality of compartments, which, when the facing members are secured thereto form a plurality of closed compartments. Therefore, to provide a communication between the various compartments, an auxiliary notch I60 is cut adjacent each notch IGb. Figures 2 and 3 particularly illustrate this construction, and it is to be understood that various other means may be employed to provide the required communication between the various chambers, such as holes in the faces of the strips I611.

Inorder to minimize twisting of the several strips along the longitudinal axis thereof, the strips Ilia are made thick (broad) on their edges, and of relatively soft and lightweight material such as the fibre insulating board previously mentioned. Strips having a thickness of one-half inch, or more, have been found to be satisfactory, and it has been observed that strips of this thickness provide sufficient contact area with the inside It is to be understood also that the abutting edges of the rails 24 and stiles 26 may be mortised or dove-tailed to provide additional mechanical strength for the framework without departing from the spirit of this invention. Likewise, it is to be understood that the framework is preferably constructed of wood or other relatively hard material having the required proportions to accommodate conventional hardware such as latches, door knobs, hinges, etc.

As illustrated in Figure l, the facing members I2 preferably consist of composite plies of wood veneer having the grain of one crosswise with respect to the grain of the ply 2|. A conventional water-resistant adhesive 23 secures the plies together, and, as well known in the art, such an adhesive may comprise a composition including, casein or phenol-aldehyde resin.

As indicated in Figures 1, 4, 5 and 6, the rail 24 is provided with an aperture I5 for receiving a connection to a fluid pressure such as steam or air.

With reference to Figure 5, it will be observed that the connection comprises a conduit I4, which conduit is connected to a suitable source of fluid pressure. A valve I I is interposed in the conduit I4, which valve is opened and closed by the handle I3. In Figure 5 the valve is illustrated in a ply 22 arranged a closed condition, while, in Figure 6, the valve is illustrated in open condition.

As further illustrated in Figure 5, the conduit I4 is enlarged at 6, and a sleeve 8 is slidably mounted thereon. A rubber sleeve I is disposed upon conduit I4 between the enlarged end 6 and slidable sleeve 8. It is to be observed that handle I3 is provided with cams I0, one on each side of valve II, that engage the slidable sleeve 8, and that the cams III are constructed and arranged to move the sleeve 8, longitudinally along the conduit I4 and compress the rubber sleeve 1, when the valve I I is moved to an open condition.

Thus, as illustrated in Figure 6, when the connector is inserted into the aperture I5 in the door rail, and the valve handle I3 actuated to open the valve, the rubber sleeve I is compressed, thereby sealing the connection in the said aperture. Similarly, when the valve handle I3 is actuated to close the valve, the rubber sleeve 7 restores to its normal shape, as illustrated in Figure 5, thereby enabling the connector to be easily withdrawn from the aperture IS.

A conventional hot-plate press is illustrated in Figure 4, which press is shown loaded with a plurality of doors for processing. The numerals 2 3 and 26 designate the rails and stiles of the respective doors, and the numeral I5 designates the aperture into which the pressure connector is inserted.

As illustrated in Figure 4, each door assembly is disposed between conventional heated-platens, which platens are connected, via suitable flexibleconnections, to asteam supply-line 25 for heating the respective plates. The top platen 21a is usually fixed to the upper cross-head 22 of the press, while the intervening platens 2'! are slidably mounted between the tie-rods 2 I. The usual discharge pipes for the platens are not shown, and it is to be understood that these are provided.

It is also to be understood that the press is provided with a suitable means for retaining the platens in open or spaced relation, when the ram I8 is lowered, which means is represented by rods I9 upon which the platens rest when the ram I8 is lowered. The numeral 20 designates a conduit connection to a fluid pressure unit for actuating the ram l8.

In practicing the present invention the grids I6, rails 24, stiles 26 and facing members I2 are assembled with the proper adhesive distributed uniformly and continuously between the abutting edges and surfaces of the various parts. The doors thus assembled are then loaded into a heated platen press, as illustrated in Figure 4.

A pressure connector is inserted into each rail aperture I5, and, substantially simultaneously with the application of external pressure to the door assemblies via ram I8, fluid pressure, preferably air, is applied via each respective pressure connection into the interior of each door assembly. While not shown, it is to be understood that a master valve may be associated with the fluid pressure connection from conduits I4, which masing of the glue joints are effected in approximately 6 minutes, when the platensare maintained at a temperature of 250 to 280 F.

Therefore, it will be evident that, during processing, the platen press provides heat and pressure for curing the adhesive thus bonding the parts into an integral structure, and the internally applied pressure forces the facing members if into perfectly flat engagement with the faces of the platens and retains them in this condition throughout the bonding operation. .Thus, the facing members I! are retained perfectly flat and the. relatively-soft grid I6 is protected against the otherwise injurious effects of the 100 1b. pressure applied by the platen press alone.

Having thus described my invention, I claim:

1. The method of making a hollow structural unit having two facing members of relatively thin material and a core structure between the facing members composed of a frame of relatively hard material and spacer members of relatively soft material disposed within the frame which comprises; assembling the facing members and the core structure as aforesaid with an adhesive interposed between the abutting faces thereof; applying a relatively high pressure to the external face of each facing member, and substantially simultaneously therewith applying a'lower pressure to the internal face of each facing member to oppose the relatively higher pressure applied to the external faces of the facing members.

2. The method of making a hollow structural unit having two facing members of relatively thin material and a core structure between the.

facin members composed of a frame of relatively hard material and an element of relatively soft material disposed within the frame for spacing the said facing members which comprises; assembling the facing members and the core structure as aforesaid with an adhesive between the abutting faces thereof applying pressure to the external face of each facing memher, and substantially simultaneously therewith applying pressure fluid into the interior of the hollow unit having a pressure lower than that applied to the facing members, to oppose the higher pressure applied to the external faces of the facing members; and heating the structural unit while maintaining the pressures as aforesaid to bond the aforesaid abutting faces by the adhesive interposed therebetween.

3. The method of making a hollow structural substantially simultaneously therewith applying pressure fluid into the interior of the hollow unit at approximately 80 lbs. per squareinch to opposethepressureappliedtotheexternalfsces of the facing members.

4. The method of makin a hollow panel having two facing lamina of relatively thin material and a core structure between the facing lamina composed of a perimetrical frame of relatively hard material and spacer members within the frame of relatively soft material, which comprises; assembling the facing lamina and the core structure as aforesaid with an adhesive interposed between the abutting faces of the core and facing lamina; applying heat and pressure to the external face of each facing lamina sumcient to effect bonding of the aforesaid abutting faces, and, simultaneously therewith, applying pressure fluid into the interior of the hollow panel at a pressure less than that applied to the external faces of the lamina but sufllcient to prevent collapse of the spacer members of the core structure.

5. The method of making a hollow structural unit having two facing members of relatively thin material and a core structure between the facing members composed of intercrossed strips of relatively soft material and a frame of relatively hard material surrounding the edges thereof, which comprises; assembling the facing members and the core structure as aforesaid with anadhesive interposed between the abutting faces thereof; applying heat at approximately 250 to 280 F. and pressure at approximately 100 lbs. per square inch to the external faces of the facing members, and, simultaneously therewith, applying pressure fluid into the hollow spaces between the facing members formed by the intercrossed strips and frame at approximately lbs. P r square inch.

6. The method of making a hollow. panel having two facing lamina of relatively thin material and a core structure between the facing lamina composed of a perimetrical frame of relatively hard material and spacer members within the frame of relatively soft material, which comprises: assembling the facing lamina and the core structure as aforesaid with an adhesive interposed between the abutting faces of the core and facing lamina; applying heat and pressure to the external face of each facing lamina, and, simultaneously therewith, applying pressure fluid into the interior of the hollow panel at a pressure less than that applied to the external faces of the facing lamina.

7. The method of making a hollow panel having two facing members of relatively thin material and a core structure between the facing members composed of a perimetrical frame of relatively hard material and an element of relatively soft material within the frame for spacing the said facing members, which comprises; assembling the facing members and the core structure as aforesaid with an adhesive interposed between the abutting faces thereof; clamping the internal faces of the facing members to the abutting faces of-the core structure under pressure to effect bonding therebetween. and. substantially simultaneously therewith, applying pressure fluid into the interior of the hollow panel at a pressure less than the aforesaid bonding pressure but sufficient to prevent collapse of the spacer elements of thecore structure.

OLIVER CLARENCE DAVIS.

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