IMPROVEMENTS IN AUTOGRAPHIC INDICATORS FOR TESTING AND OTHER MACHINES WHERE FLUID PRESSURE IS EMPLOYED
Year: 1884

page_text: I JOSEPH HARTLEY WICKSTEED of Joshua Buckton and C Limited of Well
House Foundry, Leeds in the County of York Engineer do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN AUTOGRAPHIC INDICATORS
FOR TESTING AND OTHER MACHINES WHERE FLUID PRESSURE IS EMPLOYED" to
be as follows:-
This indicator acts by fluid pressure bearing upon a ram piston or plunger and
in order to do away with the retarding action of the stuffing box rotary motion is
imparted to the indicator ram. The fluid pressure is counterbalanced by a spring
pressing against the ram and against a suitable abutment in a spring box and the
spring with its box is made to revolve simultaneously with the ram. Other
suitable counter pressure may be used instead of the spring The spring box and
the ram each have a separate spur wheel keyed upon them which are driven by a
pinion with a long face of tooth. Thus the ram is free to advance or retire in its
pressure cylinder and approach or recede from the wheel upon the spring box.
The method of driving may however be varied.
The rain is prolonged through the spring box and at a convenient place it carries
a pencil which moves with the traversing motion of the ram; and by marking a
paper or equivalent registers the movements of the ram. The Invention is adapted
for hydraulic testing machines, punching or shearing machines hydraulic presses
hydrostatic weighing machines or other apparatus where fluid pressure is employed
or applicable and from which a diagram is required and for making diagrams of
the behaviour of a specimen in a testing machine. For this purpose the paper
mounted on a cylinder the axis of which is parallel to the axis of the ram and
attachments are so made to the specimen that by a cord coming from the attach-
ments this cylinder is made to revolve in response to the extension or other
distortion (if so desired) of the object operated upon.
is
A constant length of cord is maintained between one of the attachments and the
diagram cylinder by means of radius bars and pulleys over which the cord passes
so arranged that the only movement of the specimen which is imparted to the
cylinder is an alteration of distance between the two attachments on the specimen.
The pressure cylinder of the indicator is put into fluid connection with a cylinder
that participates in the strain put upon the specimen and thus the pencil of the
indicator moves in response to the strain upon the specimen or object,

page_text: The two movements in combination produce a diagram of which one dimension
represents the altered shape of the specimen and the other dimension represents
the degree of strain carried by the specimen and when my Invention is applied to
other than testing machines any ordinary method may be employed for imparting
such motion to the cylinder as in combination with the movements of the ram will
make the desired record.
In testing machines using my indicator it is preferred that the strain put upon
the specimen should be balanced by dead weights or weighted levers so that the
dimension of the diagram indicating pressure may have its value verified by the
ascertained dead weight that balances that strain at any part of the diagram.
Also there may be combined with the above an arrangement of clock work
giving a constant traverse to a separate pencil bearing upon the paper and this
pencil may be made to traverse parallel with the axis of the cylinder so that it
will show by the longitudinal distance that it marks from the point at which it
started what has been the duration of time throughout the autographic record.
Doted this ...

page_text: I JOSEPH HARTLEY WICKSTEED of Joshua Buckton and Co Limited of Well
House Foundry Leeds in the County of York, Engineer do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN AUTOGRAPHIC INDICATORS
FOR TESTING AND OTHER MACHINES WHERE FLUID PRESSURE IS EMPLOYED,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This indicator acts by fluid pressure bearing upon a ram piston or plunger and
in order to do away with the retarding action of the stuffing box, rotary motion is
imparted to the indicator ram. The fluid pressure is counterbalanced by a spring
pressing against the ram and against a suitable abutment in a spring box, and the
spring with its box is made to revolve simultaneously with the ram. Other
suitable pressure may be used instead of the spring. The spring box and the ram
each have a separate spur wheel keyed upon them which are driven by a pinion
with a long face of tooth. Thus the ram is free to advance or retire in its pressure
cylinder and approach or recede from the wheel upon the spring box. The method
of driving may however be varied.
The rain is prolonged through the spring box and at a convenient place it carries
a pencil which moves with the traversing motion of the ram and by marking a
paper or equivalent registers the movements of the ram. The Invention is adapted
for hydraulic testing machines punching or shearing machines, hydraulic presses
hydrostatic weighing machines or other apparatus where fluid pressure is employed
or applicable and from which a diagram is required.
For the purpose of making diagrams of the behaviour of a specimen in a testing
machine the paper is mounted on a cylinder the axis of which is parallel to the
axis of the ram and attachments are so made to the specimen that by a cord
coming from the attachments this cylinder is made to revolve in response to the
extension or other distortion (if so desired) of the object operated upon.
A constant length of cord is maintained between one of the attachments and
the diagram cylinder by means of radius bars and pulleys over which the cord
passes, so arranged that the only movement of the specimen which is imparted
to the cylinder is an alteration of distance between the two attachments on the
specimen.
The pressure cylinder of the indicator is put into fluid connection with a
cylinder that participates in the strain put upon the specimen and thus the
pencil of the indicator moves in response to the strain upon the specimen or
object.
The two movements in combination produce a diagram of which one dimension
represents the altered shape of the specimen and the other dimension represents
the degree of strain carried by the specimen.
In testing machines using my indicator it is preferred that the strain put upon
the specimen should be balanced by dead weights or weighted levers so that the
dimension of the diagram indicating pressure may have its value verified by the
ascertained dead weight that balances that strain at any part of the diagram.
Also there may be combined with the above an arrangement of clock work
giving a constant traverse to a separate pencil bearing upon the paper and this
pencil may be made to traverse parallel with the axis of the cylinder so that it
will shew by the longitudinal distance that it marks from the point at which it
started what has been the duration of time throughout the autographic record,
J

page_text: Figure 1 Sheet 1 shews the indicator with its connection to the specimen in
a testing machine for tensile strains.
A is the indicator, B the connection, C the specimen, and D the testing machine.
In this application clips E E are attached to the specimen on datum lines at a
stated distance apart; to one of these clips the end of a cord is connected the
other clip carries a pulley F round which the cord passes and the joints between
this pulley and the fixed point, on the indicator are so arranged that the only
movement of the specimen which affects the length of the cord as between the
specimen and the indicator cylinder G is an increase of distance between the
clips E E. This is accomplished by having three joints to the connecting bars
and a pulley at each joint all the pulleys being of equal diameter and by making
the cord bear upon each of the three pulleys the connecting bars may open or close
the angles they subtend but the sum of the angles which intervene between the
two ends of the cord, which are parallel to each other amounts always to 180°.
If the distance between the specimen and the fixed point on the indicator alters,
the length of the connecting bars does not alter, it is only their angles which alter
and as it has been shewn that the sum of those angles remains the same therefore
the cord which passes along their length and around their angles remains unaltered
in length notwithstanding their movement.
Sheet 2 shows the indicator apart from its connections with the specimen, testing
machine or other object in any hydraulic machine to which it is applied. Figure 2
is side elevation. Figure 3 a sectional view in plan. Figure 4 an end elevation
and Figure 5 a cross section.
In these Figures A is a ram working in a cylinder B, which is in fluid connection
with the machine of whatever nature which is doing the work that it is required
to record. C is a spiral spring pressing upon the ram A in a direction opposite to
the fluid pressure, so that as the fluid pressure increases upon the ram the spring
becomes compressed and the ran advances out of the cylinder and as the fluid
pressure decreases the spring expands and the ram recedes into the cylinder; D is
a water tight stuffing box which surrounds the ram and in order that the friction
on this gland may not prevent the fluid pressure on the ram and the counter-
pressure of the spring coming into just equilibrium, a revolving motion is imparted
to the ram, together with the spring and the box which gives an abutment to the
spring; for this purpose the wheel E is keyed upon the ram and the wheel F upon
the spring box and these are simultaneously driven by the pinion G which has
a long face of tooth in which the wheel E travels as the ram advances and recedes.
The pinion G is driven by a belt from any suitable power running on fast and loose
pulleys H. Having now made clear this part of the Invention, I wish it to be
understood that any other suitable counterpressure might be used instead of a
spring such as the pressure from a rising column of mercury compressed air or dead
weights and also that so long as the ram and its cylinder revolve in relation to
each other it is immaterial whether the ram is stationary as regards the body of
the machine while the cylinder revolves or vice versa as described or whether the
ram carries its water tight stuffing with it or revolves within the stuffing.
Reverting to the Figures the ram is prolonged through the spring box and carries
a pencil-holder and pencil I or equivalent marking device which moves
longitudinally with the ram but does not revolve with it, and in order that
there may be no lost motion between the pencil holder and the collars on the
ram which push it to and fro one of the collars J is fixed to the ram and the other
collar K is kept up against the pencil holder by the weight L or some equivalent
pressure. The revolving motion of the ram is in the direction which tends to press
the pencil upon the cylinder M and the cylinder is surrounded with the paper on
which the record is made. It will now be seen that as the ram advances or recedes
in response to the increase or diminution of fluid pressure the pencil I marks the
paper on the cylinder nearer to the one end of it or the other. The cylinder is in
connection with the object of which the behaviour is being registered so that the
circumferential position of the line marked by the pencil indicates as may be

page_text: desired certain movements of the object while the longitudinal position of the line
indicates the corresponding fluid pressure. The circumferential movement of the
cylinder may be modified in various ways according to the object that has to be
registered, but when the instrument is applied to testing machines this movement
is effected in the manner described with reference to Figure 1. Lost motion is
prevented in moving this cylinder by the counter weight N, the cord from which
is carried round the cylinder M or round a pulley on the end of it, the weight N
pulling in the opposite direction to the cord from the sample.
O is any convenient arrangement of clock work, actuating the screw Pat
whatever rate it may be desired to draw a line upon the paper by the pencil Q the
longitudinal position of which will shew the time at which the indications of
pressures were made.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
First. The application substantially as described of a revolving motion to the
ram of an autographic indicator where fluid pressure is employed.
Second. The use for the purposes above mentioned of connecting bars and pulleys
by which the connection is made between the specimen under test and the indicator
barrel substantially as described.
Third. The combination of parts forming improved indicating apparatus such as
is above described and illustrated in the annexed Drawings.
Dated this 22nd day of June 1884.
JOSEPH HARTLEY WICKSTEED.