US517975A

US517975A - Plimmon h

Info

Publication number: US517975A
Authority: US
Publication date: 1894-04-10
Anticipated expiration: 1911-04-10

Description

(No Model.)

P. H. DUDLEY.

METHOD OF TESTING METAL BARS.

No. 517,975. PatentedApr. 10, 1894'.

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UNITED STATES PATENT O FICE.

PLIMMON H. DUldLEY,OF'NEW YORK, N. Y.

. METHOD OF TESTING METAL BARS.

SPECIFICATION forming part of Letters Patent No. 517,975, dated April 10, 1894.

Application filed April 11, 1893. Serial No. 469,857. (N0 specimens.)

To all whom it may concern: I

Be it known that I, PLIMMON' H. DUDLEY, of New York, in the county and State of New York, have invented a new and useful Improvement in Methods of Testing Bars of Metal, of which the'following is a specification.

My invention relates to an improvement in the method of testing bars of metal and more particularly steel railway rails,to ascertain the elongation and compression of the metal at the same time that its resistance to lateral strain is determined. It has been common in testing rails, to submit a piece of the bar cut from the end of the rail to the impact of a heavy weight directed toward a portion of the bar about midway between its supports and at right angles thereto to determine whether or not the rail is capable of withstanding the required lateral strain without breaking. The elongation of the rail, viz.,

the amount which it may be stretched without cleaving,has been subsequently, or by a separate operation, determined by making a piece of the bar or rail of a certain predetermined area in cross section and then applying weight tending to pull it apart in the direction of its length. This has been a matter requiring no little expenditure of time and labor-particularly where it was desired to test each rai1before laying it for use.

I have found, particularly in the manufacture of railway rails, that a sufficiently accu-, rate test of elongation may be made simul-' taneously with the test of lateral strain, and my present method consists in providing the bar or rail to be tested along the portion to be submitted to the greatest strain, with a series of marks a predetermined distance apart before the impact from the weight takes place and after the impact noting the change in the marks upon both its head and base, and Fig.

5 represents a similar section in the form which it assumes after receiving the impact upon its side as distinguished from its head 7 or base.

I have shown cross sections of the several rail pieces at the left of the pieces.

The head of the rail is denoted by A in the several figures, its base by B and its web by.

O. The supporting blocks are denoted by D.

The marker which I find it convenient to use consists of an oblong head piece E, provided witha series of perforations for receiving the shanks e of a series of pointed cutters or scorers e. The points of the scorers are arranged with great precision, at predetermined distances from one another and are made very hard to indent the rails. When worn, they may be replaced by simply removing the old and inserting the new one. When placed upon the rail section. or piece, upon that part to be scored, as shown in Fig. 1, the marking or scoring may be done by simply tapping the back of the marker with a hammer.

The marks made on the bottom of the base are indicated by 1); those on the top of the head by a; thoseon the side of the base by b and those on the side of the head by a.

The lengthening of the distance or distances between the marks on the side of the rail opposite that on which the impact takes place, determines the elongation, while the shortening of the distance or distances be tween the marks on the side of the rail on which the impact takes place, determines the compression of the rail.

The time required to mark the rail and to subsequently measure the changed distances between the marks is slight and the single impact of the weight serves to impart the necessary strain for determining both the lateral resistance and the elongation.

While I have shown a marker with seven cutters or scorers, the number is a matter of choice as is also the distance between two successive cutters. I have, however, found i it convenient in practice to place them one inch apartmaking six equal spaces extending along the rail in opposite directions from the intended center of impact. As it would require a great expenditure of time andlabor to so adjust the piece of rail with respect to the path of the lowermost point of the heavy Weight, which produces the impact, as to make the apexof the deflected portion of the rail fall at exactly the middle point of a single marked unit of a practically short length, the series of marks isapplied in such position as to extend in opposite directions from the point where the center of impact does actually take place, and hence varying curves of deflection and varying amounts of elongation at successive steps from the center of impact may be at once determined by simply noting where the center of impactdid actually occur in the series and calculating in opposite directions from that point.

What I claim is- The method of testing metallic bars or rails, consisting of laying OK on the bar or rail a series of predetermined distances, submitting the bar so prepared to lateral impact at a point Within the extreme limits of the series, and finally ascertaining the change which has taken place in the deflection and length of the distances laid ofi on the bar under the lateralimpact to which it has been subjected, to determine its condition, substantially as set forth.

PLIMMON H. DUDLEY.

Witnesses:

FREDK. HAYNES, GEORGE BARRY.