IMPROVEMENTS IN APPARATUS FOR TESTING THE STRENGTH OF MATERIALS
Year: 1857

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in
the County of Middlesex, and of 166, Buchanan Street, in the City of
Glasgow, North Britain, Gentleman, for the Invention of "IMPROVEMENTS
IN APPARATUS FOR TESTING THE STRENGTH OF MATERIALS."-A communication
from Francis C. Lowthorp, of Trenton, in the County of Mercer, and
State of New Jersey, United States of America.
Sealed the 6th October 1857, and dated the 24th June 1857.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
24th June 1857.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN APPARATUS FOR TESTING THE STRENGTH OF MATERIALS," a communi-
cation from Francis C. Lowthorp, of Trenton, in the County of Mercer, and.
State of New Jersey, United States of America, to be as follows:
This Invention relates to a peculiar construction and arrangement of.
machinery or apparatus for ascertaining the amount of tensile and transverse-
strain, torsion, and crushing force which any material to be tested is capable of.
withstanding, and consists in employing suitable gearing and mechanism for
applying such strains or forces, in combination with a piston or plunger;
operating against a body of water or other fluid contained within a cylinder or:

page_text: barrel, so that on applying the strain or force to the object to be tested by the
aid of the gearing, such pressure shall be transmitted to the fluid in the
cylinder or barrel, and thence to any suitable indicating apparatus in con-
nection with the same, whereby the attendant is enabled to calculate readily
the amount of strain or force to which the object has been submitted.
The principal use of this Invention is to enable a succession of objects to be
tested with greater ease and facility than can be accomplished by the ordinary
arrangement of hydraulic rams, complex levers, and other cumbrous appliances
hitherto employed for that purpose.
In employing this apparatus for testing pipes, the pipe to be tested is fitted
tight at each end between two cross heads, and water is allowed to enter
therein by a suitable stop-cock. When the pipe is full of water, a hollow
ram is forced inside it through a stuffing box in one of the cross heads, and
exerts a pressure upon the water in the pipe, which pressure is conveyed
through the hollow of the ram to any suitable indicator in connection
therewith.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
24th December 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex, and
of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of June, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Henry Johnson, Her special license that I, the said John Henry
Johnson, my exécutors, administrators, and assigns, or such others as I, the
said John Henry Johnson, my executors, administrators, or assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 Islands, and Isle of Man, an Invention for "IMPROVE-
KENTS IN APPARATUS FOR TESTING THE STRENGTH OF MATERIALS," a communication
from Francis C. Lowthorp, of Trenton, in the County of Mercer, and State

page_text: of New Jersey, United States of America, upon the condition (amongst others)
that I, the said John Henry Johnson, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
The said Invention relates to a peculiar construction and arrangement of
machinery or apparatus for ascertaining the amount of tensile and transverse
strain, torsion, and crushing force which any material to be tested is capable of
withstanding, and consists in employing suitable gearing and mechanism for
applying such strains or forces, in combination with a piston or plunger
operating against a body of water or other fluid contained within a cylinder
or barrel, so that on applying the strain or force to the object to be tested by
the aid of the gearing, such pressure shall be transmitted to the fluid in the
cylinder or barrel, and thence to any suitable indicating apparatus in con-
nection with the same, whereby the attendant is enabled to calculate readily
the amount of strain or force to which the object has been submitted.
The principal use of this Invention is to enable a succession of objects to be
tested with greater ease and facility than can be accomplished by the ordinary
arrangement of hydraulic rams, complex levers, and other cumbrous appliances
hitherto employed for that purpose.
In employing this apparatus for testing pipes, the tube to be tested is fitted
tight at. each end between two cross beads, and water is allowed to enter
therein by a suitable stop-cock. When the pipe is full of water, a hollow
ram is forced inside it through a stuffing box in one of the cross heads, and
exerts a pressure upon the water in the pipe, which pressure is conveyed
through the hollow of the ram to any suitable indicator in connection
therewith.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed; the
same letters of reference indicate corresponding parts throughout all the
corresponding Figures.

page_text: Figure 1 of the accompanying Sheet of Drawings represents a longitudinal
side elevation of the improved testing apparatus complete; Figure 2 is a
corresponding plan of the same; Figure 3 is an end view of the apparatus,
looking in the direction of the arrow 6 in Figure 2; Figure 4 represents a
transverse section of the apparatus taken along the line 1, 2, in Figure 2;
and Figure 5 is an end elevation of the same, looking in the direction of the
arrow 7 in Figure 2.
The principal framing of the apparatus consists of two strong longitudinal
beams, composed respectively of the pieces A, B, and C, and A', B', and C¹.
These two compound beams are placed at a suitable distance apart, and are
connected together by the three transverse beams D, D', and D2, and the
whole is stayed by means of the diagonal braces b, b, which impart a firmness
and solidity to the entire structure. The intermediate pieces B & B¹ are
made narrower than the top and bottom pieces, and are so placed as to leave
a groove on the inner sides of the two main beams, as is clearly shewn in
Figure 4. Across one end of these longitudinal beains are secured an upper
transverse beam E, and a lower beam F; to the former are attached tlie ends
of two short longitudinal beamis G, G¹, the opposite ends of which rest upon
and are secured to the transverse beam I, which, together with a similar cross
beam J, is firmly secured to the main longitudinal beams. A light frame or
standard, composed of the uprights e, e, and cross piece F, is erected upon
the two cross beams I and J. This constitutes the entire framing of the
apparatus, which may of course be extended to any required dimensions,
according to the uses to which it is to be applied. Near one end of and
between the two main beams, is secured the short cylinder K, the transverse
horizontal centre line of which corresponds to the grooves in the inner sides of
the main beams. This cylinder is bored out perfectly true, and is furnished
with end covers 9, 9', a piston stuffing box h, and piston rod L, of a similar
construction and arrangement of those of an ordinary steam engine. i and ¹
are two orifices in the upper side of the cylinder, communicating severally
with the two opposite sides of the piston in the cylinder. A pipe j (Figure 1),
connected with the indicator or pressure guage M, is capable of being
attached or coupled by a union or other convenient joint, with either one or
other of the orifices i, i, the indicator being made to slide for that purpose
along the cross piece f, so as to be readily brought over either one or other
of the two orifices. Two additional openings k, k, similar to the openings i, i,
are also made in the cylinder on either side of the pistoni, for the purpose cf
admitting air and water therein, as herein-after described. A cross head N is
firmly secured to the end of the piston rod L, and is formed with a boss at

page_text: each side, which slide in the grooves in the inner sides of the main beams, as
shewn at Figure 4. In the bosses of this cross head fit the two spindles
O and O', a collar being placed on each side of the bosses to prevent the
spindles having any movement independant of the cross head and piston rod.
The inner ends of these spindles have screw threads formed upon them, which
work in corresponding internal screws made in the bosses of a second cross
head P, of a similar construction and arrangement to the first, and sliding
in the grooves of the main beams. The piston rod L carries at its outer
extremity a large spur wheel Q, to the inner side of the boss of which is
secured a pinion R; both turning loosely on the piston rod. S, S¹, are two
pinions carried by the shafts U and U', gearing into the large spur wheel Q,
whilst the two spur wheels T and T gear into the pinion R. The spur
wheels T, T", are made fast on the outer ends of the screw spindles O and O¹
respectively, and into these wheels gear the pinions m and m¹ fast on the
short shafts n and n', which work in bearings p, p¹, secured to the under
sides of the transverse beams E and H, whilst the shafts U and U¹ work
in similar bearings and on the upper sides of these beams. The outer
ends of these four shafts or spindles are squared to receive a winch handle,
for the purpose of turning them, as shown in the Drawings. The pinions
S, S¹, and. m, m', may be made sufficiently broad to remain in gear with their
respective wheels during the lateral movement which they receive from the
piston rod L and screw spindles O, O', or they may be arranged to slide along
their several shafts, as shewn in the Drawings. A third cross head V, similar
to the two former ones, is also made to slide along the grooves inside the main
beams, but is securely confined in any desired position in the grooves by
strong keys W (Figures 1, 2, and 5), which fit into slots or mortises cut
perpendicularly through the beams at suitable intervals, in order that the
position of the cross-head may be changed to suit the article to be tested.
The two cross heads V and P have each an oblong opening made entirely
through them, and at right angles to these are made holes for the reception
of the pins 2,2', (Figure 5).
I shall now. proceed to .describe the mode of using or putting into
operation this testing. apparatus. In the case of testing the tensile strain
of a rod X with the strength of the eyes at each extremity of the same,
I first secure the cross head V in a suitable position between the main
beams by means of the keys W, and then secure the eyes of the rod in the
openings in the two cross heads. V and P by the pins q for that purpose.
The cylinder K. is now supplied, with water between the cover g and the
piston, such water, being in communication with the indicator through the

page_text: pipe. The orifice k is closed, and either or both of the orifices and at
the opposite end of the cylinder are left open to allow the air to escape freely.
The pinions S and S₁ being placed in gear with the large spur wheel Q, the
whole machine is ready for working. Suppose the rod K to have a sectional
area, for example, of one inch, and it be desired to submit it to a tensile strain
equal to two tons to the inch, and suppose the piston in the cylinder to have a
superficial arca of 224 square inches, whilst the indicator connected therewith
is divided to represent the pressure per square inch in pounds. The attendant
or attendants now turn, by means of winch handles, one or both of the shafts
U, U, in the direction of the arrows, and thereby transmit a rotatory motion
through the large spur wheel Q, pinión R, and smaller spur wheels T, T¹, to
the two screw spindles O, O', which turn in the direction shewn by the arrows
in Figure 3, and as these are both right-handed screws it is obvious that the
cross head P will be drawn towards the cross head N, thereby subjecting the
rod X to a tensile strain, which gradually increases as the wheels are rotated.
As this strain is born also by the cross.head N in connection with the piston,
it follows that should the pointer on the face of the pressure guage M reach
one hundred pounds, the tensile strain upon the rod X will be equal to one
hundred times the area of the piston, and as I have stated that this area is
224 inches, it follows that the strain will be 22,400 lbs. or ten tons. The rod
having been tested the wheels are turned in a contrary direction, and the
cross head P being thus made to approach the cross head V, the pins 9, 9',
may be taken out and the tested rod removed from the apparatus to make
room for a succeeding one.
When it is desired to ascertain the crushing or compressing force which
any material will sustain, the cross head V is secured in proximity to the
cross head P, whilst the indicator is connected with the orifice i', the orifice k
being closed, and the two other orifices i and k left open; the gearing is now
rotated in a contrary direction to that indicated by the arrows, so as to cause
the cross head to approach the cross head V, and thereby exert a crushing
or compressing action upon the material which is placed between them until
the required amount of compression is arrived at, which is indicated by the
pointer of the pressure guage, in the manner herein-before described, the
water being introduced into the cylinder on the opposite side of the piston to
that in which it is introduced when the apparatus is used for ascertaining the
tensile strain.
The facility with which an article may be subjected to a transverse or
binding strain will be readily seen by a practical man, without the neces-
sity of any further description thereof. For the purpose of expediting

page_text: the movements of the screw spindles O and O' during certain portions. of
their operations, the actuating winch handles are removed from the shafts
U and U', and are fitted on to the ends of the shafts n and n¹; and as
the pinions m and m¹ gear directly into the spur wheels T, T, it is evident
that the movement of the screw spindles will be more rapid than before, and
consequently that the apparatus can be quickly adjusted for the reception of
articles of varying sizes.
When it is desired to submit a shaft to a torsional or twisting strain,
I place the shaft 3 (Figure 1), which is to be tested in plummer blocks
2, carried by the main beams, and secure it firmly therein by means
of keys to prevent it from turning. A wheel or pulley 4 is also keyed firmly
on to the shaft to be tested, and this wheel is partially surrounded by a
chain, one end of which is secured to the periphery of the wheel whilst the
other end is attached to the cross head P. The gearing is now put into
action, being rotated in the direction of the arrows until the pointer of the
pressure guage arrives at the required indication on the dial. This, with the
leverage of the wheel or pulley 4 taken into consideration, will give the amount
of torsional strain required.
Figure 6 of the Drawings represents a sectional plan of a modified arrange-
ment of apparatus adapted to the testing of pipes. a and b are two cross heads
connected together by the rods c, c. To the cross head a is attached a three-
way cock d, fitted with a supply branch e, and waste water branch f, either
one of which can be made to communicate with an orifice in the cross head-
by suitably turning the plug of the cock. A third cross head, shewn in section
at g, is arranged to slide freely over and along the screwed portion of the
rods c, c, and is furnished with a stuffing box h for the reception of the
plunger i, the latter being made hollow and fitted or formed with a cross
bark, which serves to guide it and prevent it from turning; to this cross bar,
is connected the end of the screw spindle 7 in such a manner that the latter
may be free to rotate but not to have any longitudinal motion independant of
the plunger. This screw spindle works through a corresponding internal
screw or nut in the cross head b. Supposing it be required to test the pipe m,
the nuts n, n, are screwed back, the pipe is introduced longitudinally between
the cross heads a and g, and the nuts are then tightened. up again for the
purpose of firmly securing the pipe between the two cross heads, a packing
ring o, of leather, india-rubber, or other suitable material, being interposed
between the ends of the pipe and the cross heads to prevent leakage. The
interior of the pipe is now filled with water or other liquid through the supply
branch e; the cock d is then closed and the screw spindle is so turned as

page_text: to force the hollow plunger i into the interior of the pipe, as shown in the
Drawing, thereby causing a pressure against the water in the same, which
pressure is communicated through a lateral opening in the head of the
plunger to a pressure guage or other suitable pressure indicator attached to
the cross bar k, when the amount of pressure to which the pipe has been
submitted may be readily calculated.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that I do not confine or restrict myself
to the precise details or arrangements which I have had occasion to describe
or refer to, as many variations may be made therefrom without deviating from
the principles or main features of the said Invention; nor do I claim any of
the mechanical elements of which the said apparatus and parts of apparatus
are respectively composed, as being, separately or apart from the use or
application of such elements to form the combination constituting such
apparatus and parts of apparatus respectively, as being any part of the said
Invention; but what I consider to be novel and original, and therefore claim
as the Invention secured to me by the herein-before in part recited Letters
Patent, is,
First, the general constructions, arrangements, and combinations of appa-s
ratus for testing the strength of materials, as hercin-before described.
Second, the combination of gearing and other suitable mechanism for
applying strains or forces to the object or material to be tested with a piston
or plunger operating against a body of water or other fluid contained within a
cylinder or barrel, so that on applying the said force or strain such a pressure s
may be transmitted to the fluid and to any suitable indicator with which the
fluid is in communication, for the purpose of readily calculating the amount of
strain or force exerted upon the object or material which is being tested.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, the Twenty-fourth day of December, One thousands
cight hundred and fifty-seven.
J. HENRY JOHNSON.
(L.S.)