US1668869A - Plaster-board lath - Google Patents

Description

May 8, 15928."

0. L.- ROUTT ET AL PLASTER BOARD LATH Filed 06t- 27, 1925 Patented May 8, 1%28.

UH'I'EED EQATENT ORVILLE I. RO'UTT AND ROBERT M. GREENIIEAF, OF LOS ANGELES, CALIFORNIA, AS- SIGNORS TO PLASTOID PRODUCTS, INC., OF LOS ANGELES, CALIFORNIA, A. COR- PORA'IION OF CALIFORNIA.

PLASTER-BOARD LATE.

Application filed October 27, 1925. Serial No. 65,121.

Our invention has among its salient objects to provide an improved plaster board of the character which includes a plastic matter between surface sheets and which has hardened, our improvement consisting in the nature of thedepressions made in the face of the article whereby to roughen the surface sheet and break or fracture the sheet adjacent the depression whereby to make possible a better bond of the plaster with the surface sheet. It is known that the plaster applied to these plaster board lath will adhere to a suitable surface sheet on the board and will adhere to the sheet, particularly when said sheet is roughened or broken so as to give a rough edge. When this roughened edge is made in connection with a depression, a very satisfactory plaster board lath is formed. We have shown two forms of our invention, one of said forms being made by depressing the paper into the body of the article so as to stretch the paper and slightly break it at the edge of the depression, leaving the edges rough, and being wholly below the plane of the surface sheet, while the other form of the invention is provided with an increased bonding surface extending above the plane of said surface sheet by bunching the surface sheet in spots and stretching it down into the depression even to the extent of break ing it and leaving its edges rough.

In order to explain our invention, we have illustrated one practical embodiment thereof on the accompanying sheet of drawings, which we will now describe.

Figure 1 is a fragmentary, perspective view of a plaster board lath, embodying our invention;

Figure 2 is a fragmentary sectional view showing one form of depression; and

Figure 3 is a similar view showing the other form of depression with the surface sheet crimped or bunched at the edge of a depression.

In the drawings, the plaster board lath shown consists of the two surface sheets, 1 and 2, with the body of plastic matter or composition therebetween, which in and of itself is old and forms no part of this invention apart from the other features to be described.

. We have discovered that we can form a very efficient plaster lath by making depressions into one side of the board after it is formed, such depressions being of any desired'form, but made by depressing the surface sheet down into the body of the material by stretching it and even to the extent of slightly breaking the sheet at the edges of the depression so as to leave roughened edges adjacent the depression, said depres sion being designated 4, and the roughened edges being designated 5, and thus forming means for establishing a holding bond between the plaster board and the coat of plaster to be applied thereto, and forming no protrusions above the plane of the surface sheet, as will be clear from Fig. 2 of the drawings.

In Fig. 3, we have shown how the process can be carried a little further and by holding the depressing fingers or elements by which the depressions are formed, the sur face sheet is gathered into bunches at the edge of the depression, as at 7, being moved sufficiently and stretched down into the depression that said sheet is torn or broken away from the body thereof adjacent said depression, as at 6, leaving two rough edges of the paper, and the crimped part thereof, and thus greatly increasing the bonding surface of the article, for when the crimped or bunched paper hardens and the broken edges become dry and hard, a good bond can be secured between them and the plaster as the latter is applied thereto.

We do not make the depressions so deep that the surface sheet is torn to any extent in order to expose edges of the composition of which the board is made, but stretch the paper down into a slight depression and slightly break the paper at one or two edges, substantially in the manner indicated. We have found also that by using depressing fingers which will form a depression having converging sides and with the broken edges converging substantially in the manner indicated, that the coat of plaster wedges into these angles with a beneficial effect. We do not, however, limit our invention to any particular form of depression, except as we may be limited by the hereto appended claims.

We claim:

1. Plaster board lath of the character referred to having a body of plastic material with cover sheet and provided with a series of depressions 111 which the paper cover sheet is pulled apart to form ragged edges to expose the plastic material on an inclined "side 01 said plaster board lath having a series of concaved depressions formed by a jab to depress the cover sheet into the plastio material, said cover sheet being pulled apart at one side of the depression 'with ragged edges exposing the plastic material between said ragged edges on an inclined surface below the plane of the surface of said board lath.

3. Plaster board lath having a plurality of depressions made in one face thereof, each depression having its cover sheet pulled apart so as to form ragged edges exposing the body of said board between said ragged edges eacli depression also having its cover sheet bunched at the opposite side thereof to form Wrinkles, whereby said ragged edges, exposed body and wrinkled cover sheet form an effective bond With plaster applied thereto;

Signed at Los Angeles, Los An'geles County, California, thi's'l9 day of October, 1925.

'ORVILLE L. ROUTT. ROBERT M. GREENLEAF.

Images