IMPROVEMENTS IN APPARATUS FOR TESTING SPRINGS, AND OTHER PURPOSES
Year: 1873

page_text: LETTERS PATENT to Heber Duckham, of Millwall, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
TESTING SPRINGS, AND OTHER PURPOSES."
Sealed the 13th March 1874, and dated the 20th December 1873.
PROVISIONAL SPECIFICATION left by the said Heber Duckham at the
Office of the Commissioners of Patents, with his Petition, on the
20th December 1873.
I, HEBER DUCKHAM, of Millwall, in the County of Middlesex, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS FOR TESTING SPRINGS, AND OTHER PURPOSES," to be as follows:-
My Invention relates to hydraulic apparatus for testing the strength
of springs for railway rolling stock, and other uses, and also for testing
iron and other materials.
It is well known that springs apparently precisely similar differ
widely in actual strength and rate of deflection, so that an undue
proportion of the weight of a locomotive or carriage is sustained by
the wheels under the more rigid springs, while the weaker springs
transmit little or no weight whatever,

page_text: By means of the machine of my Invention carriage and buffer springs
may be readily classified in accordance with the depression indicated
under given strains, so that they may be accurately paired or assorted
according to the work required of them.
The machine which is characterized by its simplicity of construction
consists of an inverted cylinder mounted upon a cast-iron frame rising
from a suitable base plate or foundation upon which the spring to be
tested is placed with the ends, in the case of a carriage spring, resting
on sliding shoes moving in guides in the foundation plate to allow of
its extension when deflected or straightened under pressure. The ram
projects at the lower end of the cylinder so that it may be brought to
bear on the spring, and is fitted with a scale to show the extent of its
movement which is recorded thereon by a pointer, so that an accurate
chart of the deflection of the spring under any desired strain is obtained,
the amount of pressure applied being indicated by a gauge on the
cylinder. The latter is provided with suitable valve gear, and is worked
by hydraulic pressure obtained either from existing mains where available,
or a separaté force pump.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Heber Duckham in the Great Seal Patent Office on
the 18th June 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HEBER
DUCKHAM, of Millwall, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of December, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Heber Duckham, Her special
licence that I, the said Heber Duckham, my exécutors, administrators,
and assigns, or such others as I, the said Heber Duckham, my executors,
administrators, and assigns, should at any time agree with and no others;
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel,

page_text: the parts necessarily constructed of a sufficient strength to sustain
the greatest strain to be applied to the spring to be tested; D is
the ram projecting from the lower end of the cylinder through the
opening in the top of the frame B, so that it may be brought to
bear upon the spring placed upon the base plate C beneath it, as
shown. The ends of the spring (in the case of a leaf spring) rest
upon sliding shoes C¹ fitted to move in guides planed in the base
plate C to allow of the extension of the spring when deflected or
straightened under pressure; E is a rod attached to the ram and
moving therewith, upon the face of which a scale is marked to show
the amount of deflection; or if a pernament record is desired a strip
of paper or card is attached to the rod E, the extent of movement
being marked thereon by a spring pencil or marker F fitted in a
socket on the frame B. By this means an accurate chart of the
deflection of the spring under any desired pressure is obtained, the
amount of pressure applied being indicated by a Bourdon or other
suitable pressure gauge G fixed on the top of the cylinder A. The
latter may be operated either by steam or by hydraulic pressure. The
ram is provided with double cup leather or other packings, so that
it may both be raised and lowered by the power; H is a valve box
enclosing an ordinary slide valve or any other suitable valve which
controls the admission of the water or steam to the pipes I, K, leading
to the upper and lower ends of the cylinder A. This valve is worked
by a lever handle L; M, pipe from the pump or boiler, and N, a waste
pipe leading to a cistern; O is an aperture in the base plate for clearing
the centre part of the spring or buffer when flattened.
In conclusion I would observe that in employing the machine for
testing a bar of iron, for instance two suitable pedestals or blocks
would be laid or bolted on the slides at any distance required for
such test, upon which blocks the bar of iron or other material would
be placed in order that the ram may descend upon it to bend or
break it at the will of the operator. In either case the deflection can
be ascertained by the divided scale E.
-
When testing metal, wood, or cement for crushing, the hole in the
base plate would be covered with a strong iron plate, the surface being
flat. The material is laid on it, and the ram having a suitable plate
secured to its end is forced down on the material, and the pressure and
deflection are ascertained by observing the indicators E and G.

page_text: Having described the nature of my Invention, and the manner of
performing the same, I declare that what I claim as the Invention
to be protected by the herein-before in part recited Letters Patent
is, the improved machine herein described consisting of an inverted
cylinder provided with ram and with proper valve gear, and combined
with gauge to indicate the pressure, and scale with pointer to show
amount of deflection, the said cylinder being mounted on a frame
rising from a base plate fitted with sliding shoes for the spring to rest
upon, the whole being constructed and arranged substantially as and
for the purpose set forth.
In witness whereof, I, the said Heber Duckham, have hereunto
set my hand and seal, this Eighteenth day of June, in the
year of our Lord One thousand eight hundred and seventy-
four