US530305A

US530305A - Bicknell hall

Info

Publication number: US530305A
Authority: US
Publication date: 1894-12-04
Anticipated expiration: 1911-12-04

Description

(No Model.) v

B. HALL.

TUBE FOR USE IN EXPANSION JOINTS. No. 530,305. Patented Dec. 4, 1894.

UNITED STATES PATENT OFFICE.

BICKNELL HALL, or TAU omMAssAoHUsETTs, ASSIGNOR or ONE-THIRD TO EDWARD P. COLEMAN, OF SAME PLACE.

TUBE FO USE IN EXPANSION-JOINTS.

SPEGIFIOATION forming part of Letters Patent No. 530,305, registered December 4, 1894.

Application filed August 24, 1894- To all whom it may concern.-

Be it known that I, BICKNELL HALL, of Taunton, in the county of Bristol and State of Massachusetts, have invented a new and useful Improvement in Tubes for. Use in Expansion-Joints, so-called, Condensers and Feed-Water Heaters, and the Like, of which the following is a specification.

My invention is an improvement on the corrugated tube which has been extensively used under the circumstances referred to to take up the expansion and contraction due to changes of temperature.

From long experience I have found that when a piece of corrugated tubing is constantly expanding and contracting a very. large percentage of the bending dueto expansion and contraction falls upon thosecorrugations which are Weaker or thinner than the others so that the wear is not distributed equally and the tube wears out sooner than itshould.

My invention is intended to remedy this fault and it consists in a piece of tubing which is not corrugated but is indented in lines across the axis of the tube by a series of short indentations which are so arranged that each indentation breaks joints with the indentations on each side of it and is separated at each end from the next indentation in line by a blank space, the natural curvature of the tube.

My invention will be understood byreference to the drawings, in which Figure 1 is an elevation partlyin section of a piece of tubing embodying my invention, Fig. 2 being a cross section on line 2 2 of Fig. 1.

A represents the indentations above described, B being the portions of plain tube lying between the ends of the indentations and 0 being those portions of the plain tube which lie between the lines of indentations. In cross section these indentations are preferably curved as will be understood from Fig. 1, but the length of each indentation is less than the circumference of the tube so that each indentation extends only part way SerialNo. 521,255. (No model.)

round the tube. In the drawings each inden tation is somewhat less in length than a quar- 5o ter of the circumference of the tube and each indentation breaks joints so to speak, with the indentations'in the line next it on each side. By this means I find that the strain tending to change the length of these tubes is 'dis- 5 5 t-ributed very evenly throughout the length of tube.

The number of indentations may well depend upon the diameter of the tube or upon the thickness of the metal, and the lines of 6c indentations may be annular as shown or a spiralline of indentations may be used, with substantially the same result. I prefer for general use however, the annular indentations, four in numberas shown. Such a tube as I have described may be made upon a collapsible grooved mandrel which is set up in a turning lathe so as to be rotated. The tool is an ordinary roller of proper dimensions to form the indentation, a portion of the periphery of the tool being removed so as to leave the part B of the tube untouched. This tool is mounted in a tool stock in the ordinary way and held against the tube. 7 5

The process of manufacture will be easily understood in all its details by those skilled in tube working. 7

What I claim as my invention is as follows:

1. The tube above described provided with a series of indentations lying in a line or lines across the axis of the tube, each indentation being less in length than the circumference of the tube, as set forth.

2. The tube above described provided with a series of indentations arranged in a line or in lines across the axis of the tube, each indentation being separated from the indentation at each end of it'and breaking joints with the indentations at each side of it, as set forth.

In testimony whereof I have hereunto set my hand this 14th day of August, 1894:.

BIOKNELL HALL.

Witnesses:

PERCY U. KENWAY, GEORGE O. G. CoALE.