IMPROVEMENTS IN APPARATUS FOR. TESTING THE STRENGTH AND DUCTILITY OF METALS, METALLIC AND OTHER STRUCTURES OR ARTICLES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by William Thomas Henney
Carrington at the Office of the Commissioners of Patents, with his
Petition, on the 1st October 1875.
$
I, WILLIAM THOMAS HENNEY CARRINGTON, of 76, Cheapside,-in the
City of London, Civil Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN APPARATUS FOR. TESTING THE STRENGTH
AND DUCTILITY OF METALS, METALLIC AND OTHER STRUCTURES OR ARTICLES," to be
as follows:-
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The first object of my Invention is so to secure wires or bars of iron,
steel, or other metals, in clips at either end of the length to be tested
that it shall be impossible for the wire or bar to turn round in the clips,
when one or both of those clips are caused to rotate for the purpose of
twisting the wire or bar and so measuring its ductility. For this
purpose I form one or more corrugations in the jaws or holding surfaces
of the clips at right angles to their axes of revolution so that when the
wire or bar to be tested is pressed by screwing the clips together it shall
at the point at which it is held be pressed into the form of this
corrugation or corrugations, and so be effectually prevented from turning

page_text: at the holding point. I mount these corrugated clips on a base plate, so
arranging that one of them shall be capable of revolving on its axis,
and I provide it with a handle, screw, or other appliance on the axis, for
the purpose of causing it to revolve; I further provide a screw thread
on the axis working into corresponding screw teeth in the circumference i
of a circular disc or dial plate, which by its revolution shall register the
number of turns sustained by the wires or bars to be tested. I fix tho
remaining clip so as not to allow it to revolve, but I provide a slot in
the base plate in which at pleasure it may be allowed to slide in the
direction of the axis of the wire or bar under test.
The second object of my Invention is to provide a convenient and
ready means for testing the tensile strength of wires or bars of iron, steel,
or other metals. For this purpose I provide a metal frame of suitable
length arranged by preference in a vertical position, and I provide at
either extremity of this frame axes carefully mounted with a view to ]
diminish friction as far as possible; on one extremity of each of these
axes, or if desired on the centres of them, I provide solid circular blocks
each furnished with a clip or clamp to hold fast the wire or bar to be
tested, and I bend or wind the wire or bar to be tested round the whole
or a part of the circumference of one (by preference the upper) or both a
of the circular blocks before securing it in the clips. On one of these
axes (by preference the upper one) I mount a weighted lever, and on
the other a screw wheel furnished with a worm to work it, so that by
winding the wire or bar on the circular block carried by this axis it
shall be strained, or so to speak, wound off the portion of the upper axis
block on which it has been wound or bent. The effect of this will be to
cause the weighted lever to be raised towards a horizontal position by
the revolution of the axis on which it is fixed. The amount of this
clevation I register by a pointer carried by the lever and passing over
the surface of a properly graduated quadrant; I thus ascertain the
power required to break the material under experiment as well as its
elongation.
In certain cases instead of emploving the above-mentioned worm and

page_text: and the straw be subsequently employed for the greater strains before
rupture of the sample.
In order that the weighted lever may not fall at once through its
whole are of motion on the rupture of the sample I provide a paul on
the lever, which falls into notches or teeth on a segmental rack so as to
arrest its fall close to the highest point to which it has risen.
According to another part of my Invention I provide the upper part
of a column with or as a cylinder for the reception of a hydraulic ram or
other mechanical means of raising this point, upon the head of which a
beam is supported.
To the short end of the lever I attach by suitable shackles and clips
one end of the material to be tested, the other end being similarly
attached to the bed plate of the machine or any conveniently placed
rigid point. The long end of this beam is free to rise under the action
of the ram. The free end I propose to provide with an adjustable key
and threaded rod, to the lower end of which I attach one end of a wire
or metal band or other similar article, whose opposite end is attached to
a drum before the wire or band is wound thereon. This drum is on an
axis so that it may turn and draw up the weighted lever when the
fulcrum is raised by means of the hydraulic ram or other means, the
height to which the weighted lever rises regulating and showing the
strain to which the material attached to the short end of lever is
subjected. The weighted lever moving on an axis is provided as in the
previous case with suitable pointers and graduated plates for marking
and registering the strain applied.
I also in some cases place the fulcrum of the lever on the column
without the intervention of the hydraulic cylinder or other apparatus for
raising it, and apply such cylinder or apparatus direct to the material to
be tested at the end opposite to that attached to the short end of the
lever, and by application of power at this point I raise the free end of
the lever, and by means of the weighted lever ascertain accurately the
strain applied in the manner before described.
I also apply this machine to testing metal and other structures, such
as girders, by attaching by suitable connections the short end of the lever
to them, and fixing them at a certain distance on each side of this point
to the bed plate of the machine or other fixed solid points.

page_text: My Invention further consists in the employment of a steelyard
beam supported upon movable or rigid centres or pivots at or near one
end and having a balance or weighted lever at the other, by which with
the quadrant mechanism before mentioned I can test or ascertain the
breaking or bending strain transversely or longitudinally, as required. 5
The hydraulic or other agent of power may be arranged at the base of
the column or otherwise.
be
Instead of the ram column being used for lifting purposes it may
made a fixture, and then I act upon the long end of the beam or lever
by a screw or other appliance, the indicator moving over the quadrant 1
at the same time to show the testing strain put upon the bar or other
body between the short end of the beam and the fixed lower portion or
base of the column.