AN IMPROVED DYNAMOMETER
Year: 1856

page_text: PROVISIONAL SPECIFICATION left by the said James Eives at the
Office of the Commissioners of Patents, with his Petition, on the
17th June 1856.
I, JAMES EIVES, of 17, Cornbill, London, do hereby declare the nature of
the said Invention for "AN IMPROVED DYNAMOMETER," a communication from a
foreigner resident abroad, to be as follows:-
It consists of an apparatus applicable to prime movers, imparting or commu-
nicating rotary motion, and to all machines to which a rotary motion is imparted
for the object of reducing to a given standard and registering automatically the
amount of power exerted or absorbed during any required period of time,
whether the force or velocity be constant or variable. It may be also used
to ascertain the comparative amount of power given out by various motors,
and the comparative amount of power obtained in burning fuel of different
kinds to furnish steam for engines; also to test the comparative lubricating
qualities of oils and other lubricating substances, as well as for a variety of
other purposes in the useful arts.

page_text: It may be described as composed of two parts, the measuring and the regis-
tering apparatus. The measuring part consists of a spring connection between
a driving and a driven shaft; springs are attached to a disk on the driven.
shaft, so that their outer extremities shall be acted upon by pins projecting
from a similar disk on the driving shaft when the shaft is in motion, so as to
cause such springs to bend until their resistance becomes stronger than the
power requisite to put the driven shaft in motion. The extent of the flexure
varies according to the force applied, and the driving shaft disk also changes it
relative position to a greater or less angle, according to said flexure. The
slight rotation of the driving shaft during this operation causes a pin projecting
from it, in the direction of the other shaft, to operate upon a wedged-shaped
recess formed in a sliding hub on the last-named shaft, so as to force this hub
back on the shaft. To this hub is connected by rods a grooved ring, also sliding)
on the driven shaft and moving with the hub; to the groove of this ring is
attached one arm of a lever, the other arm of which operates on a wheel, so as
to cause it to vibrate or slide on its shaft whenever the grooved ring is moved.
The shaft is connected by geer, or otherwise, to the registering apparatus, con-
sisting of a counter similar to those employed in ordinary gas or other metres,
and will cause it to register the number of revolutions the vibrating wheel will
make. The vibrating wheel rests on a disk with a toothed wheel secured
beneath it, mounted on a short shaft. -
i
This wheel connects by pinion shaft and geer other similar means with the
driven shaft, so that when the latter revolves, the disk and wheel also revolve,
and by the friction of the disk upon the rim of the vibrating wheel, turns the
latter whenever it is at any other position than at the centre of the disk. The
surface of the disk is faced with some slightly elastic substance, such as leather,
and the rim of the vibrating wheel is faced with small wheels revolving at
right angles with the plane of the motion of the wheel on which they are fixed,
and these are slightly toothed to indent in the surface of the disk, and thus
ensure the turning of the wheel when the disk turns; at the same time they
net as friction wheels to roll upon the surface of the disk when the vibrating
wheel is moved to & fro along its shaft. radially over the surface of the disk.
The vibrating wlieel is set in such manner that the portion of the rim which
bears upon the disk is at the centre thereof when the springs of the:spring
connection are not flexed, & consequently when no force is applied to turn the
driven shaft, but in proportion to the force transmitted through the springs.it
will be moved outward from the centre of the disk. As soon as the 'driven
shaft begins to revolve, this, disk, by reason of the connecting mechanism, is
also caused to revolve, and its revolution will bear a definite relation to those

page_text: of the driven shaft.. The speed with which the vibrating wheel revolves is
governed in part by the speed of the disk, anil in part by the distance to which
this vibrating wheel is moved from the centre of the disk, according to the
greater or less flexure of the springs of the spring connection. The revolutions
of the vibrating wheel, & consequently of the registering apparatus, will thus
always bear a definite relation to the compound product of the speed of the
driven shaft and of the force applied to it, and therefore make a registration
in proportion to the power transmitted.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Eives in the Great Seal Patent Office on the
12th December 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
EIVES, of 17, Cornhill, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of June, in the year of our Lord One
thousand eight hundred and fifty-six, in the nineteenth year of Her reign, did
for Herself, Her heirs and successors, give and grant unto me, the said
James Eives, Her special licence that I, the said James Eives, my executors,
administrators, and assigns, or such others as I, the said James Eives, 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
Islands, and Isle of Man, an. Invention for "AN IMPROVED DYNAMOMETER,"
a communication, upon the condition (amongst others) that I, the said Jamies
Eives, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 James Eives, do liereby declare the
naturo of my 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 Drawings which accompany this. descrip
tion, and in which Figure 1 represents a side elevation of my apparatus

page_text: applied to a rotating shaft; Figure 2 is a top view of the same; Figure 3 is a
vertical section of the same at the line a, a, Figure 1, looking toward that
extremity of the rotating shaft from which the power is taken off; Figure 4 is
a vertical section of the same at the line,, of Figure 1, looking toward that
extremity of the shaft to which the power is applied; Figure 5 is a plan on a
larger scale, of the spring driving connection and its accessories; Figure 6 is
a diagram, shewing the method of obtaining the form of a cam, which shall
compensate the unequal variation of the springs of the spring connection when
strained successively with equal increments of force; Figure 7 is a section, on
an enlarged scale, of the vibrating wheel and its shaft; Figure 8 is a plan of
the vibrating wheel and its connection, with the registering apparatus.
My apparatus, which I denominate a registering dynamometer, is applicable
to all prime movers which impart or communicate rotary motion, and to all
machines to which a rotary motion is imparted; and its object is to reduce to
a given standard, and register automatically, the amount of power exerted or
absorbed during any required period of time, whether the force be constant or
variable, and whether it act with a constant or variable velocity. It is par-
ticularly applicable to establishments where power is let out or furnished to
fénants, in which case one of my dynamometers may be applied at every point
where power is delivered to a tenant, so as to measure and register the amount
of power consumed, much in the same manner as the consumption of gas is
now registered by a gas metre. A larger instrument may also be placed at the
prime mover, which, by comparison with the others, will show the amount of
power consumed by the shafting and other mechanism by which the power is
transmitted to the various parts of the establishment. My instrument may
also be used with advantage for a variety of purposes in the useful arts, as for
example, in determining the amount of power given out of various motors; in
ascertaining the comparative amount of power obtained by burning fuel of
different kinds to furnish steam for an engine; or, in testing the comparative
lubricating qualities of oils and other lubricating substances, either simple or
compound.
In describing my Invention, it will be expedient, for the sale of clearness,
to consider the instrument as composed of two parts, one of which may be
termed the measuring apparatus, as it measures the momentary force exerted
at any instant of time; while the other part may be termed the registering
apparatus, as it registers the whole amount of power expended or consumed.
The measuring apparatus is similar in construction and operation to some
dynamometers heretofore contrived, and consists mainly of a spring connection
between a driving and a driven shaft, or their equivalents, in which connection

page_text: the springs are more or less compressed as the force exerted increases or
diminishes, and in which the change in the relative position of the parts inci-
dent to the movement of the springs under compression is employed to impart
motion to a lever, or other equivalent indicator, which will move a greater or
less distance in proportion. to the momentary force exerted, independently of
the velocity or speed of the shafts.
The registering apparatus consists of a counter, which is similar to those
ordinarily employed in ordinary gas and other metres, but which is controlled.
in such manner by the measuring apparatus, that its indications depend in part
upon the velocity or speed of the rotating shafts to which the instrument is
applied, and in part upon the force exerted or consumed, as indicated by the
relative change in the position of the parts of the spring connection of the.
measuring apparatus.
In the accompanying Drawings, the rotating shafts A and B, extend in line.
with each other, so as to constitute a continuous line of shafting. The power
is applied to the shaft A, and is taken off from the shaft B, being communi-
cated from the one shaft to the other, by means of the spring connection, which
is secured to the adjacent ends of the two shafts. This spring connection is.
composed of a disk C, secured to the shaft A, of a similar disk C' secured to.
the shaft B, and of the springs and drivers, by means of which the movement
of one disk is imparted to the other. The springs d, d, are made fast at their
inner extremities to the pins f, f, which are firmly secured to the disk C', and
they extend radially outward to the periphery of the disk. The drivers 7, 9,
project from the disk C, and bear upon the outer extremities of the springs, so
that when the shaft A is turned, the springs will be flexed in proportion to the
power required to overcome the resistance of the shaft B. This bending of
the springs permits an angular change in the position of the
to C, and this angular change will be the greater as the resistance of the
shaft B increases, and the springs bend to a greater extent; when the resistance
decreases, the springs being less strained, will tend to resume their original
positions, and the disk C will move back again toward the position which it.
occupied with respect to the other disk before the power was applied. Thus,
every variation in the amount of force expended in turning the shaft B, will be
faithfully indicated or measured, by the change in the relative angular position
of the two disks, and this angular change is employed by me to control my..
register.
disk C', relative.
The disk C, has studs e, Figures 1 and 5, secured to its face, which are:
received into and bear upon the face of wedged-shaped recesses i, formed in a
hab II, that slides freely upon the shaft B, but is compelled to turn with it by

page_text: means of a feather fitting in a groove in the hub. This hub is connected by
two rods o, o, that pass through the disk C, with a grooved ring. Hence,
when the disk C changes its angular position, or turns with respect to tho
disk C', the studs bearing upon the wedge-shaped faces of the recesses in the
hub I move the latter endwise upon the shaft B, and consequently move
the groove ring J; the hub I is pressed against the stud e, by means of.
springs D, D, which return the hub and ring to their initial position, whenever
the disk C returns to its first position with respect to the disk C'. Hence the
ring J will bo moved to and fro upon the shaft as the power consumed by the
shaft varies.
In order to make this movement of the ring available as a correct measurer
of the power, it is necessary that it should move equal distances with equal
increments of force. If the profile of the inclined face of the wedge-shaped.
recess were a straight line, the grooved ring would be moved equal distances
by equal movements of the springs; but, as springs bend progressively less
distances under progressively equal increments of force, the distances traversed
by the grooved ring would not be equal with equal increments of force.
In order to obviate this difficulty, I adapt the form of the faces of the
recesses upon which the studs act to the power of the springs, and ascertain
the exact profile which should be given to them, in the following manner :-
The shaft B is made fast, so that it cannot turn; a cord is then worked upon
the shaft A, and a weight is suspended from it. This weight bends the springs
and turns the disk C with respect to C' a certain distance, which is measured
by the number of degrees through which a point upon the disk C moves, with
respect to a corresponding point upon the disk C' additionally; equal weights
are successively added to the cord, and the number of degrees traversed by the
point upon the disk C, upon each addition are successively noted, until the
greatest weight which the springs should sustain has been ascertained. I then
by means of a scale of equal parts, construct a diagram such as shown at
Figure 6, laying off upon the line a, a, the number of degrees traversed, and
upon the lines y, y, the number of pounds in weight corresponding therewith,
and unite the points z, z, by a curve. This curve is the profile of the wedge-
formed face of the recess i, and it is plain that by the action of the studs upon
such recesses, the grooved ring will be moved along the shaft equal distances.
when equal increments of force are applied to turn the shafts.
The sliding ring J is connected to a lever E, with a vibrating wheel F,
whose periphery bears upon a disk G. The lever E is forked at its upper
extremity to enter the groove of the sliding ring; it is pivotted at V, and is
forked at its lower extremity to enter in a groove formed in the hub of the

page_text: vibrating wheel F, so that the latter is caused to vibrate upon the disk G, as
the sliding ring is moved to and fro by reason of the compression of the springs
of the spring connection. This vibrating wheel is free to slide to and fro upon
its shaft M, but the latter is caused to turn with the wheel as it is fitted with
a feather, which is received in a longitudinal slot in in the hub of the vibrating
wheel. This shaft is connected with a counter, which is similar to those
employed in ordinary gas and other metres. For this purpose its shaft has a
worin N secured upon it, whose threads gear into a screw wheel secured to a
shaft P. The latter is fitted at its opposite extremity with a pinion whose
teeth gear simultaneously into those of two cog wheels R and S. One of these
cog wheels R carries a pointer or hand 1, and the other S has a graduated
dial U secured to it by means of studs. The number of teeth in the wheel
that carries the dial is one less than that of the teeth in the wheel that carries
the hand, and as both wheels are driven by the same pinion, the hand at each
complete revolution gains on the dial an angular distance equal to the pitch of
the teeth in the dial wheel. This apparatus will thus register any number of
revolutions not greater than the number of teeth in the dial wheel. The dial
wheel revolves in close proximity to a fixed dial W, so that any portion of its
revolution is registered. Both of the cog wheels are mounted upon cannon.
shafts, the one of which runs upon the other; the inner cannon shaft runs
upon a spindle, to which a hand m is attached; the other end of this spindle.
has an arm n secured to it, whose outer extremity is connected by a link rod
with one arm of a bent lever X, the other arm of this bent lever is forked to
embrace the vibrating wheel F, and the lever is pivotted at a. Hence, as the
vibrating wheel slides upon its shaft, the hand m is caused to move over the.
dial W; the hand, therefore, indicates the extent to which the springs of the
spring connection are bent, and thus shows the momentary amount of force.
exerted at any instant.
The vibrating wheel, as has been before said, bears upon a disk G. This
disk is mounted upon a short shaft I, which has a toothed wheel secured to
it. The teeth of the latter gear into a pinion 2, which is secured to a shaft T,.
whose opposite extremity is also fitted with a pinion, whose teeth gear into the.
threads of a worm V which is formed upon the hub of the disk C'; hence, as
the shaft B revolves the disk G is also caused to revolve, and by the friction.
of its surface upon the rim of the vibrating wheel F, turns the latter when-
ever it is at any other position than at the centre of the disk. In order to.
prevent the slipping of the vibrating wheel upon the disk, the latter is faced
with leather or some other slightly elastic substance. The rim of the vibrating:
wheel is also formed in a peculiar manner, as shown at Figures 7 and 8,

page_text: I
a series of recesses being cut in its rim, in which wheels s, s, whose peri-
plieries are slightly foothed, are pivotted; the rims of these wheels thus stand
at right angles to that of the vibrating wheel, and act like cog teeth to indent
in the slightly elastic surface of the disk and ensure the turning of the vibrating
wheel when the disk turns; they at the same time act as friction wheels to:
roll upon the surface of the disk when the vibrating wheel is moved to and
fró along its shaft radially over the surface of the disk. The vibrating wheel F.
is set in such manner that the portion of the rim which bears upon the disk G
is at the centre thereof when the springs of the spring connection are not
flexed, and consequently when no force is applied to turn the driving and
driven shafts. Hence, when force is applied to turn the driving shaft A, the
drivers of the disk C secured thereto, bearing against the springs of the spring
connection, bend the latter until their tension is sufficient to overcome the
resistance of the driven shaft B; the disk C, with its shaft B, is then dragged
around with the driving shaft A, the springs bending to a greater or less extent
with the amount of force transmitted through them, from the one shaft to the.
other. The bending of the springs of the spring connection permits the disk.
of the driving shaft to turn to a greater or less extent with respect to the disk
of the driven shaft, and thus to move the sliding ring J and the forked lever E.
The latter moves the vibrating wheel outward from the centre of the disk
toward the periphery thereof, and this movement, from the peculiar shape of
the wedge-formed recess, will be in exact proportion to the amount of force"
transmitted through the springs. As soon as the driven shaft begins to revolve
the disk G, by reason of the connecting mechanism, is also caused to revolve,
and its revolution will have a definite relation to those of the driven shaft B.
The disk G in its revolution acting upon the rim of the vibrating wheel F;
causes the latter to revolve and move the registering apparatus, and the speed.
with which the vibrating wheel revolves is governed in part by the speed of
the disk, and in part by the distance to which this vibrating wheel is moved
from the centre of the disk according to the greater or less flexure of the
springs of the spring connection. If the driven shaft revolve at a constant
speed and the force vary, then the revolutions of the vibrating wheel, and con-
sequently the number registered by the counter, will vary in proportion to the
variation in the force, for it is clear that, as the wheel is moved by the flexure
of the springs, which varies with the variation in the force to a greater or less
distance from the centre of the disk, so will it be acted upon by portions of the
disk of greater or less radius, which will thus impart to it a greater or less
speed, although the speed of the disk itself is not increased. If, on the other
hand, the force remains constant while the speed of the driven shaft varies,

page_text: then the vibrating wheel, although acted upon by a portion of the disk of con-
stant radius, will nevertheless have its speed increased or diminished according
as the speed of the driven shaft and the disk G driven therefrom increases. or.
diminishes. If both force and speed vary, whether in the same or in opposite
directions, so will the speed of the vibrating wheel vary under the joint action
of a varying flexure of the springs and the varying speed of the shafts. The
revolutions of the vibrating wheel, and consequently the registration of the
registering apparatus, bearing always a definite relation to the compound
product of the speed of the driven shaft and of the force applied to it, and
therefore making a registration in proportion to the power transmitted. In
order. to reduce this registration to any known standard, it is necessary to
know the power of the springs, their distance from the centre of motion, the
proportion that the revolutions of the disk bear to the revolutions of the driven
shaft, the lengths of the arms of the forked lever E, and the diameter of the
vibrating wheel. When this apparatus is employed to test the power of any
prime mover, a friction brake or some other retarding force is applied to the
driven shaft B, and the prime mover is connected with the driving shaft A.
When it is employed to ascertain the amount of power consumed by a machine
or a train of machines, the apparatus is made to form a part of the connecting
mechanism between the prime mover and the machines to be tested, so that
the power is transmitted through the two shafts A and B. When my appa-
ratus is employed to test oils, an additional counting apparatus is connected
with the disk G to register the number of revolutions made. A friction brake
is applied to the driven shaft B, and is lubricated with a given quantity of the
oil to be tested until the whole is exhausted; the number of revolutions made
up to the time when the brake begins to heat, and the power absorbed in
driving the brake are then noted, by means of which a comparison may be
instituted between the oil tested and a standard oil which has been previously
tested in the same manner.
The examples I have given are sufficient to indicate the manner in which
my Invention may be used, and to enable a skilful mechanic to apply it as
circumstances may require. It will be evident to the skilful mechanic that
various changes may be made in the construction and arrangement of my
apparatus without affecting materially the principle of my Invention; thus, for
example, any efficient registering apparatus may be employed in place of the
one I have described; springs of any kind may also be used in place of those
I have described. The mechanism for transmitting the movement of the
sliding hub to the vibrating wheel and the rotation of the shafts to the disk
may also be modified.

page_text: What I claim as my Invention and desire to secure by Letters Patent is
the registering dynamometer for rotary motion, herein described, consisting of
a registering apparatus, whose registrations are governed in part by the velocity
of the machine to which it is applied and in part by the force exerted in
putting the same in motion.
I also claim the method of correcting the indications of the apparatus for
measuring by the flexure of springs the amount of force exerted by a rotating
shaft, by means of a stud acting upon an inclined surface, the profile of which
is adapted to the peculiarities of the springs, substantially in the manner
described.
I also claim the combination of a disk having a slightly elastic surface, with
a vibrating wheel, whose rim is fitted with rotating wheels, as described.
In witness whereof, I, the said James Eives, have hereunto set my hand
and seal, this Seventeenth day of September, in the year of our Lord
One thousand eight hundred and fifty-six.
lind ind
TAXES
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ES EIVES.
(L.S.)