US3027923A - Apparatus for bending and setting of laminated materials - Google Patents

Description

April 3, 1962 c. s. SCHREIBER APPARATUS FOR BENDING AND SETTING 0F LAMINATED MATERIALS Filed Jan. 29, 1957 2 Sheets-Sheet 1 A ril 3, 1962 c. s. SCHREIBER APPARATUS FOR BENDING AND SETTING OF LAMINATED MATERIALS Filed Jan. 29, 1957 2 Sheets-Sheet 2 F167. Flqs MAX T0 @LWW United States Patent ()fiice 3,027,923 Patented Apr. 3, 1962 3,027,923 APPARATUS FOR BENDING AND SETTING OF LAMINATED MATERIALS Chaim Samuel Schreiber, Edgware, England, assignor, by mesne assignments, to Schreiber System (U.S.A.) Ltd., New York, N.Y., a company of New York Filed Jan. 29, 1957, Ser. No. 637,014 Claims priority, application Great Britain Jan. 30, 1956 2 Claims. (Cl. 144-256) The present invention relates to an improved apparatus for bending and setting laminated materials, such as wood veneers to form cabinets.

Preferred forms of the invention will now be described with reference to the accompanying diagrammatic drawings, in which:

FIGURE 1 is an elevation of a machine for bending and setting wood veneers to form the carcase of a wireless cabinet,

FIGURE 2 is a perspective view of a portion of the machine shown in FIGURE 1,

FIGURES 3 to 6 are elevations illustrating steps in the process of bending the laminae,

FIGURE 7 is a perspective view of the article coming 011 the machine shown in the previous figures, and

FIGURE 8 is an illustration of a variation of the invention.

A machine for carrying out the invention is shown in FIGURES 1 and 2. It comprises four steel supporting beams 10, 11, 12 and 13 between which are mounted seven hydraulic or compressed air jacks, 14, 15L, 15R, 16L, 16R and 17L, 17R. Also supported from the roof beam 12 is a fixed stout strut 18 on the lower end of which is rigidly and firmly secured an inner former 19 which is a solid rectangular prism with its longitudinal convex corner edges A, B, C and D rounded.

The jack 14 carries a table 20 which can be moved up and down with respect to the inner former 19. The table constitutes an intermediate part of a multi-part outer former.

The jacks 15L and 15R carry similar blocks 21L and 21R which constitute side parts of the outer former and which can be moved by the jacks towards and away from the inner former 19.

The jacks 16L and 16R carry yokes 22L and 22R between the ends of which are rollers 23L and 23R respectively.

The jacks 17L and 17R carry clamps 24L and 24R holding the ends of a flexible steel band 25.

The cylinders of the jacks 17L and 17R are pivotally mounted at 26L and 26R respectively. Any one or more of the cylinders of the jacks 14, 15L, 15R, 16L and 16R may also be similarly pivoted if desired.

The manner in which the machine is used will now be described with reference to FIGURES 1 to 7:

It is assumed for the purpose of this example of the invention that the body of a wireless cabinet is to be made of the shape shown at 27 in FIGURE 7. After it has been fashioned to the shape here shown, the carcase will be fitted with strengthening struts in its corners and elsewhere and a filler piece will be inserted to close the gap at 28. But as such finishing steps form no part of the invention they will not be described in detail.

The carcase may be formed of five rectangular sheets of plywood, in which case the three inner ones are coated on both sides with a binder and the two outer ones on their inner faces only.

Any suitable number of sheets may be used and for clearness only two have been shown in the drawings at 29, 30. The binder may be thermosetting resin.

The two or more sheets are then loosely assembled, so that their edges lie flush together, and are inserted between the flexible steel band 25 and the inner former 19 in the position shown in FIGURE 3. In order that this may be done, all of the jacks 14, 15L, 15R, 16L and 16R are previously full retracted so that the outer former parts 20 and 21 and the rollers 23 are withdrawn from the inner former 19. Similarly, the jacks 17 are previously lowered so that the band 25 lies loosely around the inner former 19.

When the laminae constituted by an assembled group of sheets with binder interposed between them have been inserted between the band and inner former, the jacks 17L and 17R are operated to pull the band 25 tight against the undersurface of the inner former 19, as shown in FIGURE 4.

Then the jack 14 is operated to force the intermediate former part 20 towards the underface of the former so that the laminae are squeezed between the inner former 19 and the block 20 which forms part of the multi-part outer former. This step in the process is illustrated in FIGURE 5. In this way air bubbles are pushed from between the laminae under the former 19 and the band serves to pull the laminae tightly around the radiused corners C and D.

The next step, illustrated in FIGURE 6, is to operate the jacks 15L and 15R to force the side former parts 21L and 21R against the left or right-hand faces of the inner former 19 so as to squeeze the side portions of the laminae between the inner and outer formers.

The final step in the bending is illustrated in FIGURES 1 and 2 and consists in operating the jacks 16L and 16R so that the rollers 23L and 23R move inwardly and downwardly towards the former 19 so as to force the two end portions of the laminae down upon the top of the inner former 19.

In this way the band 25 again holds the laminae tightly against the radiused corners A and B.

The jacks 16 are more powerful than the jacks 17 so that the clamps ML and 24R move downwardly against the pull of the jack 17 and under the influence of the heavier jacks 16. At the same time the jacks 17 pivot inwardly.

When the laminae have been bent in this way it is necessary to set the binder. This may be done merely by leaving the laminae in the machine until this binder has dried and hardened. This would be the case if the binder is Scotch glue.

For a thermosetting resin, however, quicker setting is achieved by applying heat for a few minutes to the laminae.

In carrying out this invention the heat may be applied electrically in either of two ways.

In the first way a heating element in the form of a strip of resistive metal (shown in broken lines at 31 in FIGURE 3) is lapped around the inner former 19 until it occupies a position similar to that of the bent laminae but ending in two terminals 32 and 33 also shown in FIGURE 3. After the laminae have been bent to their final position shown in FIGURES 1 and 2, a heating current of electricity is passed through the resistive element 31 and preferably also through the flexible metal band 25 so that the laminae are heated from both sides.

In an alternative method the inner metal element 31 and the flexible band 25 are used as terminals between which is passed a high frequency heating current.

When the binder, which may be a urea-formaldehyde plastic, has set, the pressures in the jacks are removed, the band 25 is allowed to go slack and the formed carcase '27 is withdrawn.

In the embodiment of the invention illustrated in FIG- ure 8 an inner former 34 is carried by a jack part 35 whilst the intermediate part 36 of an outer former is aoargeas fixed. The side members 37 and 38 of the outer former are movable in a manner similar to the parts 21L and 21R of the previous embodiment. It will be seen that the intermediate and side faces of the inner former 34 are convex and concave respectively, the outer parts 36, 37, 38 being correspondingly shaped. The apparatus is operated in exactly the same manner as that shown in the previous figlres.

What I claim is:

1. An apparatus for shaping laminated articles comprising an inner former having a plurality of faces in eluding an intermediate face, two side faces and a fourth face and at least four corners of relatively short radius bounding the adjacent edges of said faces, a multi-part outer former having an intermediate part and two side parts substantially complemental to the intermediate and two side faces of the inner former, means for moving the inner and outer formers relatively toward and away from each other, a flexible band disposed between the inner former and the outer formers and engageable with the outer surface of a laminated assembly of sheets positioned against the inner former, fluid actuated jacks engaging the opposite ends of said band and supporting said ends for movement toward and away from said formers and toward and away from each other into and out of a position opposing the fourth side of said inner former, means for actuating said jacks to move said ends of said band away from said formers for tightening it around the assembly of sheets and the intermediate and side faces of the inner former and the corners therebetween, band bending rollers engageable with the outside and extending transversely of said hand between said jacks and said inner former, and other jacks more powerful than said fluid actuated jacks for moving said band bending rollers toward said fourth face of said inner former and for moving the ends of said band into said position opposing the fourth side of said former thereby to force said assembly of sheets against said fourth face while said band is tightened by said fluid actuated jacks.

2. An apparatus for shaping laminated articles comprising an inner former having a plurality of faces including an intermediate face, two side faces and a fourth face and at least four corners of relatively short radius between the adjacent edges of said faces, means supporting said former in a fixed position, a multi-part outer former having an intermediate part and two side parts substantially complemental to and opposing the intermediate and two side faces, respectively, of the inner former, a flexible band disposed between the inner former and the outer former and engageable with the outer surface of a laminated assembly of sheets positioned against the inner former, means for moving said intermediate part of said outer former toward said inner former to press said laminated assembly against said intermediate face, jacks engaging the opposite ends of said band and supporting said ends for movement toward and away from said formers and toward and away from each other into and out of a position opposing the fourth side of said inner former, means for actuating said jacks to move said ends of said band away from said formers for tightening it around the assembly of sheets and the intermediate and side faces of the inner former and the corners therebetween, means for moving said side parts of said outer former toward said inner former to press said band against said laminated assembly and said assembly against said side faces after said band has been tightened, and bending members engageable with the outside of said band between said jacks and said outer former to move the ends of said band into said position opposing said fourth side of said former and deflect said band toward said fourth face and bend the ends of said laminated assembly toward and into engagement with said fourth side.

References Cited in the file of this patent UNITED STATES PATENTS 455,097 Deering June 30, 1891 965,927 Nichols Aug. 2, 1910 2,009,265 Hirschfield July 23, 1935 2,350,915 Miller June 6, 1944 2,416,427 Bonawit et al Feb. 25, 1947 2,442,443 Swallow June 1, 1948 2,598,363 Davis May 27, 1952 2,614,158 Sefton et al. Oct. 14, 1952 2,626,642 Weyant Jan. 27, 1953 2,632,381 Buckland Mar. 24, 1953 2,642,919 Kingman June 23, 1953

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