US408922A

US408922A - macknigiit

Info

Publication number: US408922A
Authority: US
Publication date: 1889-08-13
Anticipated expiration: 1906-08-13

Description

(No Model.)

J. W. MAGKNIGHT.

FIRE PROOF CEILING.

Patented Aug. 1-3, 1889.

May/

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IINIV/ENIWJR *Wlr M UNITED STATES PATENT OFFICE.

JOHN W. MACKNIGIIT, OF NEIV YORK, N. Y.

FIRE-PROOF CEILING.

SPECIFICATION forming part of Letters Patent No. 408,922, dated August 13, 1889. Application filed January 2, 1889. Serial No. 295,198. (No model.)

To all whom it may concern:

Be it known that I, JOHN WV. MAC-KNIGHT, of New York city, New York, have invented an Improved Fire-Proof Ceiling, of which the following is a specification.

This invention relates to an improved fireproof ceiling of great durability; and the invention consists in the various features of improvement, more fully pointed out in the claims.

111 the accompanying drawings, Figure l is a perspective view of my improved fireproof ceiling, showing it in the process of formation. Fig. 2 is avertical transverse section through the completed ceiling, but with the platform still in place.

The letters a a represent a series of parallel I-beams, from which I suspend temporarily a platform Z) by hangers 0. Upon this platform between the beams I sift a thin layer of gravel or broken stone 07.. Next, I place across the spaces between the beams a series of joists (Z, which rest upon the lower flanges of the beams. These joists should be placed at about an angle of fortyfive degrees to the beams, as shown, and the joists to the right and left of any one beam should break line, Fig. 1. Between the joists there is'now packed flush with the surface thereof a concrete mixture c, composed, preferably, of three parts of ashes, three parts of gravel, one part of cement, and enough water to give to the mass the consistency of brown sugar. hile this mass is still moist, the joists (Z are removed and the grooves thus formed are filled in with a mixture f, composed of about three parts of crushed stone (preferably crushed trap-rock) and one part of cement, to which a little ammonia, iron, and alum may be added. This mixture will thus be formed into strips that rest upon the lower flanges of beams 04. The masses 6 f will set together, and will adhere in the act of setting to form one united mass. Owing to the oblique positionof the joists (Z, the strips f will assume a similar inclination, thus assuring increased strength. The strips f are, as will be seen, formed of much stronger material than the concrete in which they are embedded. As they unite with the concrete in setting, they will strengthen the whole structure and prevent it from warping and cracking. The space above the masses 6 f should be filled in with a layer of dry'ashes or similar material 9 flush with the upper edge of beams a. The ceiling being completed, the platform I) is removed, and the usual finish is applied to the layer n of gravel.

WVhat I claim is- 1. The combination of beams a, with a series of strips f of crushed stone and cement between the beams, and with concrete 6, inelosing strips f at the sides, substantially as specified.

'2. The combination of I-beams a, with the oblique strips f of crushed stone and cement resting upon the lower flanges of the I-beams, and with the concrete 8 at the sides of strips and with a superposed layer g of ashes and a bottom layer or of gravel, substantially as specified.

' JOHN IV. MACKNIGHT. Witnesses: F. v. BRIEsEN,

HENRY E. ROEDER.