US2854373A

US2854373A - Postforming process

Info

Publication number: US2854373A
Application number: US300320A
Authority: US
Inventors: William I Beach
Original assignee: North American Aviation Corp
Current assignee: North American Aviation Corp
Priority date: 1952-07-22
Filing date: 1952-07-22
Publication date: 1958-09-30
Anticipated expiration: 1975-09-30

Description

158 w. l. BEACH 2,854,373

I POSTFORMING RROCESS Filed July 22, 1952 2 Sheets-Sheet 1 fiiiiiilllliii) FIG.2'

FIG.3

INVENTOR.

WILLIAM I. BEACH I ATTORN EY Sept. 30, 1958 w. l. BEACH POSTFORMING PROCESS 2 SheetS-Sheet 2 Filed July 22, 1952 FIG. 6

INVENTOR.

WILLIAM n. BEACH FIG.

MAM/51K ATTORNEY Patented Sept. '30, 1958 POSTFORMING PROCESS William I. Beach, Los Angeles, Calif., assignor to North American Aviation, Inc.

Application July 22, 1952, Serial No. 300,320

2 Claims. (Cl. 154-110) This application is a continuation in part of my copending application for Postforming Process and Article, Serial No. 62,074, filed November 26, 1948, in the name of William 1. Beach, now abandoned.

This invention pertains to method and apparatus for utilizing the invention disclosed and claimed in Patent Number 2,433,643. That patent covers the postforming of certain materials by the application of heat Within certain limitations of time and temperature, forming the material while so heated, and allowing it to cool in its new form. The material so postformed normally has suflicient flexural rigidity characteristics to enable it to be attached structurally in operative position for the intended purpose of the end products resulting therefrom. However, in certain fields of operation, such as for decorative purposes wherein exposed surfaces reflect artistic configurations and warm and pleasing colors, protuberances such as screw heads, moldings, fastenings, and the like, are undesirable. Further, it is customary practice to support such decorative surfaces by attaching thereto, on the undersides thereof, materials having bulk characteristics for purposes of reinforcement and to prevent lateral deflection resulting from their normal use in applications such as table tops, sink tops, cabinets, or the like. The angularly arranged portions of the aforementioned items complicate fabricating techniques when it is desired to obtain a one-piece coved article.

In this connection, the decorative plastic surface is composed of a base of a relatively thick sheet of several layers of paper or fabric material, or the like, impregnated with a suitable heat-hardening resin such as phenol formaldehyde. To this base is applied a decorative layer of paper, with a preselected design and color imprinted thereon, over which is applied a coat or layer of transparent resin of the type such as melamine, urea, or phenolic. Materials such as these are presently being postformed by the use of the process described in Patent No. 2,433,643. However, when coved panels are desired, difficulty has been experienced in attaching the postformed product such as decorative plastic to a preformed backing structure to produce a pleasing contour Without introducing surface defects attributable to normal fabricating methods. This difficulty has been overcome, according to the present invention, by attaching the structural supporting elements or the backup members to the sheet of decorative material prior to postforming. In the past it has been necessary to individually and separately preform the plastic sheet material and structural supporting members into coved shapes, and then join or assemble them by conventional fastening or gluing methods. This has been unsatisfactory because of difficulty in obtaining the uniform connection between the decorative sheet and backing members throughout the horizontal and vertical surfaces. This is particularly so when members are arranged angularly with respect to each other since fabricating tolerances seldom permit these parts to match perfectly. The preforming and assembly method is further objectionable because of ex- United States Patent fiice pensive equipment necessary to apply gluing pressures to contoured surfaces. Obviously, this increases the pro duction cost.

Accordingly, it is an object of this invention to facilitate the production of postformed items having attached supporting structures.

It is a further object of this invention to attach supporting or backup structures to material prior to postforming the same.

It is yet another object of this invention to provide an arrangement for economically producing fiat sheets of postforming material having attached thereto supporting or backup structural shapes.

Further objects of the invention will become apparent from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a perspective view of an arrangement of the invention;

' Fig. 2 illustrates forming of the material illustrated in Fig 1;

Fig. 3 illustrates a finished product made in accordance with the teachings of Figs. 1 and 2;

Fig. 4 is a view of an arrangement for forming an outside cove;

Fig. 5 illustrates the finished product of Fig. 4;

Fig. 6 illustrates a means for heating the material for forming;

Fig.7 is a novel arrangement of a corner;

Fig. 8 is an inside perspective view of a product formed from the layout in Fig. 7;

Fig. 9 is an outside perspective view of a product formed from the layout in Fig. 7; and

Fig. 10 is a perspective view of the arrangement for a corner prior to forming.

According to the invention plastic material 1, which is postformable in accordance with Patent No. 2,433,643, is suitably attached to backup or

structural supporting strips

2 and 3. Material 1 may comprise a layer 14 of a transparent coated decorative material which may have a design in color or figure print, and forms a part of the postformable sheet stock 1.

In the preferred embodiment of the invention, sheet 1 is bonded, glued or otherwise suitably attached to sheets or

strips

2 and 3. These may be plywood, Masonite, or other inexpensive material having required strength characteristics. The

members

2 and 3 are spaced at 5 a sufiicient distance apart to enable postformingin accordance with Patent No. 2,433,643the sheet stock 1 with the

members

2 and 3 attached thereto. This spacing between

members

2 and 3 is dependent, of course, upon the angle to which sheet 1 is to be bent and upon the thickness of the material of sheet 1. Where the material is to be bent to an angle of it is preferred to leave a space of approximately three times the radius of bend although other spacings are possible. A forming die 6 is used for obtaining the cove at 7 While a reinforcing strip 8 may be added to stiffen the finished product. It has been discovered that when reinforcing

members

2 and 3 are attached sheet material 1 may be successfully postformed by simply bending it around a single die 6 to the desired angle as illustrated in Fig. 2. This will provide a uniform, accurate bend without the necessity of employing both a male and female die.

In the application of the invention illustrated in Fig. 4, sheet material 1 is applied to reinforcing

strips

2 and 3 in a manner similar to the arrangement in Fig. 1. However, there is provided in the space 5 a die 9 having the desired radius of curvature corresponding to the finished product. This die may form a part of the finished product and serve also as a reinforcement for the outside cove thus formed. A reinforcing strip 10 is 3 provided, if desired, for strengthening the finished structure.

In postforming sheet 1 in accordance with the teachings of Patent No. 2,433,643, any of the methods of heating disclosed in that patent may be successfully used. The entire area of sheet 1 as well as

strips

2 and 3 may be heated, but for convenience and simplicity it is normally preferred to heat only the portions of the sheet where the bend is to be made. The heating may be accomplished by means of an oven, a liquid bath, by conduction from heated plates, by subjecting the material to a high frequency alternating electric field, by radiant heating, or by any other suitable means. A radiant heating arrangement such as shown in Fig. 6 has been found to be particularly satisfactory. As illustrated, radiant heating element 15 is disposed on one side of sheet 1 and provided with a suitable reflector 16 to direct the heat towards sheet 1. Heating element 15 may be disposed on either side of sheet 1, but is normally preferable to locate the heater on the side away from the bend which is to be made. If that is done it will be unnecessary to move the heater out of the way when the material is formed. If heating element 15 is disposed on the same side as the

backup strips

2 and 3 it should, of course, be disposed near space as illustrated so that there will be no danger of the backup strips shading sheet 1 at the location of the bend and thereby preventing proper heating.

Referring now to the arrangement in Fig. 7, there is shown a sheet of material to the underside of which is glued, or otherwise fastened, supporting sheet 2 and strips 3 and 4 for forming an article having a corner. Strips 3 and 4 are spaced apart a suitable distance 5 to enable postforming, which may in the preferred embodiment equal approximately three times the radius of bend of the postformed part 1. Strips 3 and 4 are provided with beveled or feathered ends at 11 and 12 to facilitate forming a finished corner when the ends are brought together as illustrated in Figs. 8 and 9. Ends 11 and 12 may be beveled or feathered before or after attachment of the supporting strips to sheet 1. For convenience this is usually done before the attachment. Thus, as illustrated, strips 3 and 4 form the support or backing for the edge portions of the article, and sheet 2 forms the support or backing for the side or principal surface thereof. In providing such a corner it will be normally necessary to provide a cutout portion 17 in sheet material 1 in space 5 at the corner as clearly shown in Fig. 7. Thus the fiat sheet of material 1 by overlying supporting sheet 2 and supporting strips 3 and 4, while having cutout portion 17 between the beveled ends of strips 3 and 4, as shown in Fig. 7, thereby defines corner forming portions. This will enable formation of the corner without difiiculty from excess material that might tend to shear or crumble, and it will permit feathered ends 11 and 12 to be neatly brought together. The exact contour of the cutout portion will depend upon the radius to which sheet material 1 is to be formed.

The present invention readily adapts itself to factory production in the following manner: The sheet material is attached to a correspondingly sized sheet of backup material, then portions of the backup material are routed out to the desired width at the areas to be postformed. Such routing can be accomplishedby the use of a rabbeting tool, saw, chisel, or otherwise, to thereby remove any desired portion or shape from the backup material.

The hereindescribed invention has many applications for instance, in connection with coved type sink tops; cabinets, where structural elements or attaching means are desired; table tops having outside coves; molding for interior decorative purposes, and many others. The invention is particularly applicable to form sink and drainboard surfaces having coved back splashes and rolled down edges. Utilization of the present invention avoids previous difficulties resulting from built-up tolerances between the overlay plastic sheet and the backing material. Further, there is avoided the laborious and costly technique previously used which comprised postforming the plastic sheet separately, fabricating the backing material, and then bonding the two materials together. The invention disclosed herein is applicable for custom jobs and is particularly adaptable to factory production because of the ease of handling the fiat sheets with the backing material attached thereto.

Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the terms of the appended claims.

I claim:

1. The process of forming from C-stage thermosetting resin-impregnated sheet material an article having a principal surface and sides defining a corner, comprising the steps of attaching to one side of a sheet of such material a rigid backing member having at least two adjoining edges; attaching to said side of said sheet at least two additional backing members so as to provide adjacent each of said edges of said firstly mentioned backing member an additional backing member having an edge in spaced parallelism therewith, and ends of said additional backing members adjacent each other and in spaced relationship, whereby unbacked bendable portions of said sheet are defined between said edges of said backing members; beveling said ends divergently away from said sheet; recessing said sheet along said ends curving therefrom to the juncture of said edges of said firstly mentioned backing member; associating with each of said unbacked bendable portions a die having an edge adjacent one of said edges of said firstly mentioned backing member and a curved surface extending therefrom at a position adjacent said side of said sheet to a second die edge remote therefrom; heating said bendable portions to a postformable temperature; bending said bendable portions about said curved surface by bringing said secondly mentioned backing members to a position wherein said beveled ends are in adjacency, and said edges of said secondly mentioned backing members are adjacent said second die edges; and holding said sheet so bent until cool.

2. The process of forming from C-stage thermosetting resin-impregnated sheet material an article having a side and edges defining a corner, comprising the steps of attaching to a sheet of such material a rigid backing member having at least two adjoining edges; attaching to said sheet adjacent each of said edges an additional backing member of substantially the thickness of said firstly mentioned backing member, with an edge of each additional backing member being in spaced parallelism with an adjacent edge of said firstly mentioned backing member, and ends of said additional backing members adjacent each other and in spaced relationship, whereby said backing members define unbacked bendable portions of said sheet between said edges thereof; beveling said ends divergently away from said sheet with each end beveled in a plane parallel to the edge of said firstly mentioned backing member remote therefrom; recessing said sheet along said ends and along a curve to said juncture of said edges of said firstly mentioned backing member; associating in each of said areas of bend an additional reinforcing member having a curved surface interconnecting two edges, disposed so that a first edge of each of said additional reinforcing members is adjacent an edge of said firstly mentioned backing member, and said curved surface extends to said sheet at said edge of said firstly mentioned rigid backing member; heating said bendable portions of said sheet to a postformable temperature; bending said bendable portions so as to bring said beveled ends into substantial adjacency, and to bring each of said edges of said secondly mentioned backing members into adjacency with a second edge of an additional reinforcing member; and holding said material so bent until cool.

References Cited in the file of this patent UNITED STATES PATENTS 5 Cuppett Mar. 23, 1915 Nelson Jan. 7, 1936 Crouch Nov. 1, 1938 Crouch Nov. 1, 1938 10 6 Alexander Jan. 3, 1939 Green Apr. 25, 1939 Beach et a1. Dec. 30, 1947 Norquist Oct. 25, 1949 Norquist Jan. 30, 1951 Clements Feb. 20, 1951 Beach Aug. 11, 1953 FOREIGN PATENTS Great Britain Apr. 18, 1932

Claims

1. THE PROCESS OF FORMING FROM C-STAGE THERMOSETTING RESIN-IMPREGNATED SHEET MATERIAL AN ARTICLE HAVING A PRINCIPAL SURFACE AND SIDES DEFINING A CORNER, COMPRISING THE STEPS OF ATTACHING TO ONE SIDE OF A SHEET OF SUCH MATERIAL A RIGID BACKING MEMBER HAVING AT LEAST TWO ADJOINING EDGES; ATTACHING TO SAID SIDE OF SAID SHEET AT LEAST TWO ADDITIONAL BACKING MEMBERS SO AS TO PROVIDE ADJACENT EACH OF SAID EDGES OF SAID FIRSTLY MENTIONED BACKING MEMBER AN ADDITIONAL BACKING MEMBER HAVING AN EDGE IN SPACED PARALLELISM THEREWITH, AND ENDS OF SAID ADDITIONAL BACKING MEMBERS ADJACENT EACH OTHER AND IN SPACED RELATIONSHIP, WHEREBY UNBACKED BENDABLE PORTIONS OF SAID SHEET ARE DEFINED BETWEEN SAID EDGES OF SAID BACKING MEMBERS: BEVELING SAID ENDS DIVERGENTLY AWAY FROM SAID SHEET; RECESSING SAID SHEET ALONG SAID ENDS CURVING THEREFROM TO THE JUNCTURE OF SAID EDGES OF SAID FIRSTLY MENTIONED BACKING MEMBER; ASSOCIATING WITH EACH OF SAID UNBACKED BENDABLE PORTIONS A DIE HAVING AN EDGE ADJACENT ONE OF SAID EDGES OF SAID FIRSTLY MENTIONED BACKING MEMBER AND A CURVED SURFACE EXTENDING THEREFROM AT A POSITION ADJACENT SAID SIDE OF SAID SHEET TO A SECOND DIE EDGE REMOTE THEREFROM; HEATING SAID BENDABLE PORTIONS TO A POSTFORMABLE TEMPERATURE; BENDING SAID BENDABLE PORTIONS ABOUT SAID CURVED SURFACE BY BRINGING SAID SECONDLY MEMTIONED BACKING MEMBERS TO A POSITION WHEREIN SAID BEVELED ENDS ARE IN ADJACENCY, AND SAID EDGES OF SAID SECONDLY MENTIONED BACKING MEMBERS ARE ADJACENT SAID SECOND DIE EDGES; AND HOLDING SAID SHEET SO BENT UNTIL COOL.