US249547A - John a - Google Patents

Description

(MndeL) J. A. REED;

GOMPRESSIBLE OAST METAL PIPE.

-NQ 249,547. Patented Nov. 15,1881.

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UNITED STATES PATENT OFFICE.

JOHN A. REED, on NEW YORK, N1 Y.

COMPRESSI BLE CAST-METAL PIPE.

SPECIFICATION formingpart of Letters Patent No. 249,547, dated November 15, 1881.

Application filed June 24, 1881. (Model) To all whom it may concern:

Be it known that I, JOHN A. REED, of the city and State of New York, (formerly of Dunellen, in the State ofNew Jersey,) have invented an Improvement in Compressible Cast- Metal Pipes, of which the following is a speci fication, I

Cast-metal tubes for boilers have been made with alternate bulges and contractions, the section of the same being composed of segments of circles standin gin reverse positions. A tube of this character is represented in Letters Patent No. 192,389 grantedto me.

In my present invention the pipe is an ogee helix or spiral with circular ends, and the same is especially adapted to the cast-iron flues or water-tubes in furnaces, but the same may be placed at intervals in steam; gas, or water pipes or mains to allow for expansion and contraction without injury to the tubes orjoints.

In the drawings, Figure 1 is a longitudinal section of this tube; Fig. 2 is a cross-section a at the line as w, and Fig. 3 is an end view.

The sectionof each side of the tube is an undulatin g line or series of ogee curves, one standi ng in one direction and the other in the other direction. The convex curves are marked a and the concave curves are marked 1), and they are of equal or nearly equal radius. The tube has aconfiguration that would result from the revolution of the convex and concave curves a 1) around the axis of thetube, at the same time that an end motion is given sufficient to produce a screw form.

In order to obtain a pipe that is reliable under the various changes of temperature and compression, I make the pitch-line ofthe screw about two-thirds the diameter of the tube and the depth of the depression (forming the helical groove around the pipe) about one-quarter of the diameter of the pipe, so as to obtain the requisites of stren gth andlightness. This tube can be compressed endwise to a considerable extent without injury, although made of castiron, and the ordinary expansion and contraction can take place without injury to the tube or to the joints by which the tube is connected; hence this tube is adapted to the flues of boilers to contain water with the heat outside the tube, to use in water, gas, or steam mains or pipes, to allow of expansion or contraction, and to other uses Where a compressible cast-iron tube can be employed. At the ends of the tube the spiral terminates in a partial cylinder at d that forms a circular end to the tube, and has the axis of the tube for the center, otherwise the end of the tube would open at one side, as indicated by thesection, Fig. 3 and to strengthen the end there is either an outward or an inward flange, e.

I am aware that screw-shaped tubes have been made, but the convex and concswe curves are'not equal, and hence the strain resulting from compression is not equal on all parts of the metal. Flanges have also been employed at the ends of the tubes, and cylindrical ends to the screw-shaped tubes have also been pro posed. In my improvement the cylindrical ends are contracted so as to be smaller than the screw-shaped portion, and the extreme ends are flanged or thickened, the object of this being to allow of the necessary strength of metal between one opening and the next in the tubesheets, against which the ends of the screwshaped tubes are received, and at the same time the screw-shaped tubes can be arranged moderately close together, so as to get the maximum number of tubes into a. given space.

I claim as my invention- The cast-metal tube the body of which is an ogee helix, the convex and concave curves bein g equal, or nearly so, and theends of the tube circular, of flanged or thicker metal, and smaller than the screw, portion, but having the same axis, substantially as set forth.

Signed by me this 24th day of March, A. I).

GEo. T. PINoKNEY, HAROLD SERRELL.

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