IM- PROVEMENTS IN MACHINERY FOR TESTING THE RESISTANCE OF MATERIALS TO TENSION, COMPRESSION, AND FLEXION
Year: 1876

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, for the Invention of "IM-
PROVEMENTS IN MACHINERY FOR TESTING THE RESISTANCE OF MATERIALS TO
TENSION, COMPRESSION, AND FLEXION." A communication from abroad by
Messieurs Thomasset and Driot, of Paris, France.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 8th December 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR TESTING
THE RESISTANCE OF MATERIALS TO TENSION, COMPRESSION, AND FLEXION."
communication.
A
This Invention relates to novel arrangements of machinery for testing the
resistance of materials to tension, compression, and flexion.
First. With regard to its general arrangement applicable to all testing machines.
The general arrangement of these machines is divided into two parts, namely,
1st, the part which gives the effort or the power; 2nd, the part which measures the
resistance.
The part which gives the effort or power is composed of a sterhydraulic con-
pressor, which has the special form indicated in Figures 3 and 4, united by a tube
or press body which exists on the machine properly so called, whereby the experiment
is made. It is a cylinder of bronze of very small diameter which embeds itself
gradually in a cast-iron back by means of a screw, being itself moved by a helicoidal
wheel, two endless screws, and two fly wheels with handles. The piston when
forced in displaces the liquid, whatever it may be, and this liquid in its turn
displaces the piston, which is enclosed in the press body on the machine itself.
The characteristic feature of this apparatus is that the quantity of liquid remains
constant during all of these operations; the said liquid passes from one press body
to the other, according as the pressure is on or off, and the great advantage which
Price 1071

page_text: results from this working is that in the line of this passage neither the valves or
gearing will be subject to any shock, the lead joints serving to sustain the pressure.
The piston therefore descends very slowly, the transmission of the effort takes place
continuously; and this transmission is such that two men at most are necessary for
working machines of a power of one hundred tons. I add to this compressor a
special arrangement for rapidly winding up the bronze piston when it is at the end
of its stroke. For this purpose a ratchet wheel is keyed upon the vertical screw,
above the said helicoidal wheel; this wheel turns loosely upon the vertical screw,
and does not actuate the same, except when two pawls are in gear with the ratchet
wheel. A fly wheel is keyed upon the top of the screw in such a manner that the
screw of the piston can at will be actuated directly by the upper horizontal fly
wheel, or through the medium of the helicoidal wheel and endless screw; by this
arrangement time and power are economized.
The sterhydraulic compressor which is separate from the machine when it is to
be subject to very high pressure may be united thereto more permanently, and may
even be cast with the cylinder which receives the pressure upon the machine when
the casting of the pieces is sufficiently simple for this purpose.
The apparatus termed the sterhydraulic compressor has a still further advantage,
namely, it may attain very high pressures (500 to 1000 atmospheres) very easily for
acting upon small sections of pistons, while having great displacements for small
volumes of displaced water; therefore the parts may be comparatively small and
light.
The preceding description explains the mechanism by whose aid the effort or
power given in powerful machines serving to measure resistance to tension com-
pression, or flexion. When the machines are for light strains I employ ordinary
means, such as screws, wheels, and cranks without the hydraulic power, as described.
The part which measures the resistance is always composed of a lever with
unequal arms; to its short arm is attached the piece to be tested, and its long arın
rests, on a loose table or plate in a large basin or cistern. The said table being
separated from the liquid upon which it exerts pressure by an india-rubber
diaphragm receives directly the load of the lever, and to give equilibrium at each
instant to this load, and consequently to measure it, I put the basin or cistern which
is on the table in communication with a vessel containing mercury, in which is
mounted a glass tube open at its extremity. A moveable scale the length of the
said tube, and graduated accordingly, indicates at each instant the resistance which
the piece being tested offers to the strain.
The principal features of the arrangement above described are as follows, namely,-
1st. The mounting of the lever upon knife edges; the axis around which the
lever tends to oscillate is fixed in this lever itself, and extends beyond the lever at
each side a sufficient distance; and in these two projecting portions at each side are
fixed pieces with sharp edges. On the other hand a piece forming two lugs, and
fixed solidly on the frame of the machine, has a bore greater than the diameter of
the axis of the lever, and in each bored socket is fixed a steel bearing piece, and
made hollow and V shaped to receive the oscillating knife edges. This arrangement
has. for its object to cause the working of the lever in the same vertical plane during
the operation and moving from its central plane the points of oscillation, so that it
will be necessary to have a great width of bearing to cause an appreciable difference
in the rotation of the lever, and moreover there will be no danger of lateral
pressure or friction, which would absorb a portion of the tension communicated to
this lever; therefore the measure of the tension will be complete and exact. This
detail is completed by a small key or wedge placed in the lug piece in each socket,
and above the centre of the axis of the lever. This key or wedge projects in such
a manner as to serve as a rest for the lever when the machine is not working, but
when once the knife edges are in action the lever axis no longer touches the keys,
and there exists all around this axis a visible space which prevents any friction of
the axis, for the reason above stated. The jaws to which the piece being tested is
attached near the lever is also knife-edge mounted, and with corresponding bearing

page_text: pieces on the lever; but in such a way that when at rest it is supported by a piece
which it leaves when once in tension not to be any more in contact therewith till
the stoppage of its knife edge with the lever.
The mounting of the lever in mymac hines is always such that the two lines of
the square passing by the three points of contact of the lever are rigourously, one
vertical (that of the small arm) and the other horizontal (that of the large arm);
this large arm transmits therefore a perpendicular force to the plane of the table,
which is horizontal, and thus prevents any lateral component from tending to turn
aside a part of the force transmitted, or from preventing the measure of totality of
the effort to which the piece being tested is submitted.
In my arrangement of the manometrical table 1 may so combine the relation
of the arms of the lever and the acting surface of the manometrical table that the
height of the mercurial column shall be reduced to practical dimensions; also I may
increase at will the fractions of weight visible in the scale, that is to say, I may
increase the sensitiveness of the machine in also causing the acting surface of the
table to vary at will.
I can also have as desired, without changing anything else in the machine, for a
machine capable of giving a total force of 50 tons, a manometrical table and its
scale for a force of 10 tons, another for a force of 25 tons, and still another for
50 tons, all three moving on the same machine, and the three mercurial scales of the
same height would give indications all the more sensible in proportion to the small-
ness of the forces used.
The arrangement of my mercury vessel allows the level of the mercury to be
seen at all times, the machine being at rest, and hence the essential arrangement of
having the indicating scale moveable at will, so that if through any cause whatever
the quantity of liquid contained in the vessels, or the dead weight of the pieces
reposing freely on the caoutchouc diaphragm should vary before the experiment, it
will be sufficient to bring the zero of the scale to the level of the mercury without
any other difficulty.
The general arrangement of the part which measures the resistance is applied to
all my machines, and is a chief characteristic of them.
Having described the general arrangement of all my testing machines, and
specified the principal points of the Invention, I will now describe three special
arrangements.
1st. A special arrangement of the machine for tension, Figures 1, 2, 3, and 4.
The press body A is traversed by a piston P in differential section and is made of
cast metal; the course of the piston is from front to back. This piston bored
hollow is traversed by a steel screw C, which on one end carries the jaw D and on
the other end the fly wheel nut E. The said fly wheel nut E remains always
attached to the piston by the aid of the divided collar R.
This arrangement has for its object to enable the jaw D when required to grasp
the piece to be tested, whatever may be its length, and to cause the steel or iron
nut E to support the effort of tension; also to put upon the piece to be tested an
initial tension sufficient for it to take its bearings before commencing the operation.
F is a second jaw drawing on knife edges on the lever G, also knife-edge mounted.*
This lever G rests on a table supported on a diaphragmn, and the pressure which it
receives is balanced at each instant by the mercurial column K; H is a mano-
metrical table on which is supported the lever G; L is the frame of the machine;
B is the sterhydraulic compressor sending the pressure into the press body in a
continuous manner and without shock.
This arrangement is characteristic, and the advantages obtained therefrom are
important, considered in connection with experimenting.
The arrangement of fixed jaws, Figures D and F is a part of this Invention;
each jaw has at its end two square claws, and the jaws are perfectly measured as to
thickness. The square claws allow of there being placed within them special small
moveable jaws, whatever may be their form, and which carry the piece being tested.

page_text: The small moveable jaws abut against the square sides of the fixed jaws, and
being measured to the same thickness as these latter, the piece being tested becomes
centred of itself without any other aid. I wish to point out that this form of fixed
jaws is a part of my Invention, as it allows of all the usual tests being made without
changing.
Secondly. Special arrangements for compression and tension tests are shewn
clearly at Figures 5 and 6, and in them the same facility is displayed for bringing
back the jaws to the required distance, and the arrangement of the machine is such
that the same manometrical table serves to measure the efforts of tension or com-
pression. This is an important part of my Invention.
A is a cylinder or press body which receives the pressure of the sterhydraulic
compressor through the tube T; B is a moveable piston, the head of which receives
four columns C attached to the front cross head D2, the whole resting upon the
moveable rollers F, F; D¹ is the back cross head; H is the screw which operates
the tension on the piece, being tested when the piston B advances; I is the fly
wheel nut, which allows of putting the jaws K', K, at any required distance apart.
K is a fixed jaw, and the tension effected on this jaw is transmitted integrally by the
two tie rods P, P, and the knife edge R to the lever L, which is supported on the
manometrical table M, and indicates the pressure on the scale. For compression the
piece being tested is placed at E; the piston acts directly on the fixed cross head
attached to the jaw K²
It will be seen that in this machine it is by no means the measure of the hydraulic
pressure which gives the measure of the resistance of the piece being tested. The
Jatter is measured directly, the piece under test being always a connection between
the force and resistance.
Thirdly. Special arrangement for testing deflection, Figures 7 and 8.
This special arrangement forming a part of my Invention relates particularly to
the manner in which the rail or other article is tried. The two knife edges C and D
actuated by the handles E, F, are regulated for the desired removal with regard to
the centre and to the knife edge L.
As
Two supporting rollers H and G serve for rolling the iron into place, and for
placing it perfectly horizontal by the aid of the ratchet or other suitable means, as
shewn at I, which causes the supporting rollers to move in a vertical direction.
soon as the iron is in place on the three knife edges the supporting rollers are
brought down and the iron is supported only on the three knife edges during
the test.
In this machine A is the body of the press; B is the cross head receiving the
effort;
C and D are the moveable knife edges against which the rail is supported ;
E, F, are handles for displacing the knife edges C, D, and to vary as desired the
relative position of the points of support; G, H, are the supports regulating the
position of the rail in a horizontal direction; I is a ratchet lever for working the
supports G and H; K is a moveable piston in the cylinder A; L is a fixed knife
edge in the piston K which gives the deflection to the rail; M is a counter-balancing
lever to bring the piston backwards; N is a tube conducting to the gauge which
indicates the force of the deflection or compression; O is the tube leading to the
compressor; R is the registering apparatus.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 7th
June 1877.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR TESTING

page_text: THE RESISTANCE OF MATERIAls to Tension, Compression, AND FLEXION.'
munication from abroad by Messieurs Thomasset and Driot, of Paris, France.
A com-
This Invention relates to novel arrangements of machinery for testing the
resistance of materials to tension, compression, and flexion.
I will first describe its general arrangement applicable to all testing machines.
The general arrangement of these machines is divided into two parts, namely,
1st., the part which produces the strain or power; 2nd., the part which measures
the resistance.
The part which produces the strain or power is composed of a sterhydraulic
compressor, which has the special form indicated in Figures 3 and 4, united by a
tube to a press body which exists on the machine properly so called, whereby the
experiment is made. This apparatus comprises a cylinder or plunger of bronze of
very small diameter, which is forced gradually into a cast-iron socket by means of
a screw moved by a helicoidal wheel, two endless screws, and two fly wheels with.
handles. The plunger when forced in displaces the liquid, whatever it may be, and
this liquid in its turn displaces the piston, which is enclosed in the press body on
the machine itself.
The characteristic feature of this apparatus is that the quantity of liquid remains
constant during all of these operations; the said liquid passes from one press body
to the other according as the pressure is on or off, and the great advantage which
results from this manner of working is that in this passage neither the valves or the
transmission of the strain will be affected by shocks or intermissions, the lead joints
serving to sustain the pressure. The piston therefore descends very slowly; the
transmission of the strain takes place continuously, and this transmission is such
that two men at most are necessary for working machines of a power of one
hundred tons. I add to this compressor a special arrangement for rapidly raising
the bronze plunger when it is at the end of its stroke. For this purpose a ratchet
wheel is keyed upon the vertical screw above the said helicoidal wheel; this wheel
turns loosely upon the vertical screw, and does not actuate the same except when the
two pawls are in gear with the ratchet wheel. A fly wheel is keyed upon the upper
end of the screw in such a manner that the said screw can at will be actuated
either directly by this upper fly wheel, or through the medium of the helicoidal
wheel and endless screws. By this arrangement time and power are economized.
The sterhydraulic compressor, which is separate from the machine when it is to
be subject to very high pressure, may be united thereto more permanently, and
may even be cast with the cylinder which receives the pressure upon the machine
when the construction of these parts is such as to permit the casting of the same
conveniently.
The apparatus termed the sterhydraulic compressor has a still further advantage,
namely, it may attain very high pressures (500 to 1000 atmospheres) very easily
for acting upon small areas, while having great displacements for small volumes of
displaced water, therefore the parts may be comparatively small and light.
The preceding description explains the mechanism by whose aid the strain or
power is produced in powerful machines serving to measure resistance to tension,
compression, or flexion. When the machines are for light strains I employ such
ordinary means as screws, wheels, and cranks without the hydraulic power, as
described.
The part which measures the resistance is always composed of a lever with
unequal arms; to its short arm is attached the piece to be tested, and its long arm
rests on a loose table or plate in a large basin or cistern. The said table is
separated by an india-rubber diaphragm from the liquid upon which it exerts
pressure, and is subjected to the direct pressure of the load in the said lever; and to
maintain equilibrium under this load, and consequently to measure it, the basin or
cistern below the said table is placed in communication with a vessel containing
mercury, in which is mounted a glass tube open at its extremity. A moveable scale,
which extends along the said tube, and is graduated accordingly, indicates at each
instant the resistance which the piece being tested offers to the strain.
This ap-

page_text: paratus is therefore properly speaking a mercurial balance in which all adjustment
of the weights by hand is avoided.
。
The most important and novel features of the apparatus above described are as
follows, namely
1st. The mounting of the lever upon knife edges; the axis around which the
lever tends to oscillate is fixed in this lever itself, and extends beyond the lever at
each side a sufficient distance; and in these two projecting portions, at each side,
are fixed pieces with sharp edges. A piece forming two lugs, and fixed solidly on
the frame of the machine, has a bore greater than the diameter of the axis of the
lever, and in each bored socket is fixed a steel bearing piece, and made hollow and V
shaped to receive the oscillating knife edges. The object of this very important
arrangement is to cause or ensure the working of the lever in the same vertical
plane throughout its action while moving away from its central plane the points of
oscillation, so that it will be necessary to have a great displacement of its supports
or bearings to cause an appreciable difference in the rotation of the lever, and more-
over there will be no danger of lateral pressure or friction which would absorb a
portion of the force communicated to this lever, therefore the measure of the tension
will be complete and exact. This construction is completed by a small key or
wedge placed in the lug piece in each socket and above the centre of the axis of the
lever. This key or wedge projects and serves as a rest for the lever when the
machine is not working, but when once the knife edges are in action the lever axis
no longer touches the key, and there exists all around this axis a visible space which
prevents any friction of the axis for the reason above stated. The holder, to which
the piece being tested is attached near the lever, is also knife-edge mounted on
corresponding bearing pieces on the lever, but in such a manner that when at rest
it is supported by a piece which it leaves when once in tension, and will not be again
in contact therewith till the stoppage of its knife-edge with the lever.
The mounting of the lever in my machines is always such that the two lines of
the square passing by the three points of contact of the lever are accurately
vertical and horizontal, that is to say, that of the small arm is vertical, and that of
the large arm is horizontal; this large arm transmits therefore a perpendicular
force to the plane of the table, which is horizontal, and therefore there is no lateral
tendency to turn aside a part of the force transmitted or to prevent the measure
of the total strain to which the piece being tested is subjected.
Other novel and important features of this arrangement of the manometrical
table are as follows, namely:-The possibility of so combining the connection of
the arms of the lever and the acting surface of the manometrical table that the
height of the mercurial column shall be reduced to practical dimensions; also the
possibility of increasing at will the fractions of weight visible on the scale, that is
to say, increasing the sensitiveness of the machine by varying as desired the acting
surface of the table.
I can have as desired, without otherwise changing the machine, for a machine
capable of giving a total force of 50 tons a manometrical table and its scale for a
force of 10 tons, another for a force of 25 tons, and another for 50 tons, all three
moving on the same machine; and the three mercurial scales of the same height
would give indications all the more sensible in proportion to the smallness of the
forces used.
The arrangement of my mercury vessel allows the level of the mercury to be
seen at all times, the machine being at rest, and hence arises another essential
feature of this Invention, namely, the employment of an indicating scale movable at
will, so that if through any cause whatever the quantity of liquid contained in the
vessels or the dead weight of the pieces reposing freely on the caoutchouc
diaphragm should vary before the experiment it will be sufficient to bring the zero
of the scale to the level of the mercury.
The general arrangement of the part which measures the resistance is applied to
all my machines, and is one of their chief characteristics.
Having described the general arrangement of all my testing machines, and

page_text: specified the important and novel features of this Invention, I will now describe
three special arrangements, namely, one for tension; one for compression, and one
for flexion.
1st. The special arrangement of the said machine for testing tensile strains is
shewn in Figures 1, 2, 3, and 4.
The press body A is traversed by a piston P, which has a differential section of
cast iron; the stroke of the piston is from front to back. This piston, bored
hollow, is traversed by a steel screw C, which on one end carries the jaws or
holder D, and on the other end the fly-wheel nut E. The said fly wheel nut E
remains always attached to the piston by the aid of the divided collar R.
This arrangement has for its object to enable the jaws D when required to grasp
the piece to be tested, whatever may be its length, and to cause the steel or iron
nut E to sustain the tensile strain; also to put upon the piece to be tested an
initial tension sufficient to take its bearings before commencing the operation.
F is a second pair of jaws bearing on knife edges on the lever G, and also knife-
edge mounted. This lever G rests on a table or plate supported on a diaphragm,
and the pressure which it receives is balanced at each instant by the mercurial
column K; H is the said manometrical table on which the lever G bears; L is the
frame of the machine; B is the sterhydraulic compressor sending the pressure into
the press body in a continuous manner and without shocks.
This action is characteristic, and the advantages obtained therefrom renders this
machine very valuable for experimental purposes.
The arrangement of fixed jaws or holders D and F is a novel feature of this
Invention; each has at its end two square claws, and the jaws are accurately
measured as to thickness. The square claws allow of there being placed within them
special small movable jaws, whatever may be their form, and which hold the piece
being tested. The small movable jaws abut against the square sides of the fixed
jaws, and being measured to the same thickness as these latter the piece being
tested will be truly centred of itself without any other means. This form of the
fixed jaws is an important part of my Invention, as it allows of all the usual tests
being made without change.
2ndly. Special arrangements for compression and tension tests are clearly shewn
in Figures 5 and 6, wherein the same facility is provided for bringing back the
jaws to the required distance; and the arrangement of the machine is such that
the same manometrical table serves to measure the strains of tension and of com-
pression. This is an important feature of my Invention.
A is a cylinder or press body, which receives the pressure of the .sterhydraulic
compressor through the tube T; B is a moveable piston, the head of which is
secured upon four columns C attached to the front cross head D2, the whole resting
upon the rollers F, F; D' is the back cross head; H is the screw which causes the
tension on the piece being tested where the piston B advances; I is the fly-wheel
nut, which allows of setting the jaws or holders K¹, K, at any required distance
apart; K is a fixed jaw, and the tension applied to this jaw is transmitted by the
two tie rods P, P, and the knife edge R to the lever L, which is supported on the
manometrical table M, and indicates the pressure on the scale. For compression,
the piece being tested is placed at E, the piston acts directly on the fixed cross
head attached to the jaw K².
It will be seen that in this machine it is by no means the measure of the
hydraulic pressure which gives the measure of the resistance of the piece being
tested. The latter is measured directly, the piece under test being always between
the force and the resistance.
3rdly. The special arrangement for testing flexion is shewn in Figures 7 and 8.
This part of iny Invention relates particularly to the manner in which a rail or
other article is tried. The two knife edges C and D actuated by the handles E, F,
are adjustable to any desired distance with regard to the centre and to the knife
edge L.
Two supporting rollers H and G serve for rolling the rail into place and for

page_text: placing it horizontally by the aid of a ratchet or other suitable means, as shewn at I;
When the
which will cause the supporting rollers to move in a vertical direction.
rail is in place on the three knife-edges the supporting rollers are brought down
and the rail is supported only on the three knife edges during the test.
In this machine A is the body of the press; B is the cross head receiving the
strain; C and D are the movable knife-edges against which the rail is supported;
E, F, are the handles for adjusting the knife-edges C, D, and for varying as desired
the relative position of the points of support; G, H, are the. supports for regulating
the position of the rail horizontally; I is a ratchet lever for working the supports
G and H; K is a movable piston in the cylinder A; L is a fixed knife-edge in the
piston K, which produces the deflection of the rail; M is a counterbalancing lever
to bring the piston backwards; N is a tube extending to the gauge, which indicates
the force of the deflection or compression; O is a tube extending to the compressor;
R is the registering apparatus.
Having thus fully described the said Invention as communicated to me by
my foreign correspondents, and the manner of performing the same, I wish it
understood that I claim, the novel construction and arrangement of the parts of
machines for testing the strength or resistance of materials under tension,
compression, or flexion, as shewn in the accompanying Drawing, and as above
specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Seventh day of June, in the year of our Lord One
thousand eight hundred and seventy-seven.
W. ROB™ LAKE. (L.S.)