AN IMPROVED FRICTION DYNAMOMETER
Year: 1854

page_text: LETTERS PATENT to William Balk, of Ipswich, in the County of Suffolk,
for the Invention of "AN IMPROVED FRICTION DYNAMOMETER."
Sealed the 12th September 1854, and dated the 3rd July 1854.
PROVISIONAL SPECIFICATION left by the said William Balk at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
July 1854.
I, WILLIAM BALK, of Ipswich, in the County of Suffolk, do hereby declare
the nature of the Invention for "AN IMPROVED FRICTION DYNAMOMETER " to be
as follows:-
The strap or instrument used for producing the friction in this dyna-
mometer is connected with the ends of an unequal armed lever, which causes
any shifting of the strap or instrument to increase or decrease its pressure on
the friction wheel, thus adjusting it so as to produce the exact amount of
friction necessary to keep the load up. This dynamometer does not require
lubrication; it is therefore independant of any manual attendance during trial,
and for this reason the more certain to lead to a true result.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Balk in the Great Seal Patent Office on the
3rd January 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BALK, of Ipswich, in the County of Suffolk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of July, in the year of our Lord One
thousand eight hundred and fifty-four, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said William Balk, Her special licence that I, the said William Balk,
my executors, administrators, and assigns, or such others as I, the said
William Balk, my executors, administrators, and 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 Ire-
land, the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
FRICTION DYNAMOMETER," upon the condition (amongst others) that I, the said
William Balk, 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 samo to be filed
in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Balk, 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 thereof (that is to say):-
.
The strap or instrument used for producing the friction in this dynamometer
is connected with the ends of an unequal armed lever, which causes any shifting
of the strap or instrument to increase or decrease its pressure on the friction
wheel, thus adjusting it so as to produce the exact amount of friction necessary
to keep the load up. This dynamometer does not require lubrication; it is
therefore independent of any manual attendance during trial, and for this
reason the more certain to lead to a true result.
Having thus stated the nature of my said Invention, I will proceed to
describe the manner of performing the same.

page_text: rigure i is a plan or a dynamometer constructed according to my inven-
tion; Figure 2 is a side elevation; and Figure 3, an end elevation thereof.
In each of which Figures the same letters indicate similar parts, and the
Drawing is to a scale of one and a half inches to a foot.. a, a, is the framing;
6 is the axis, which has its bearings at c, c, as shown. On the axis b is fixed
the drum, which receives motion by a strap g from the engine or power to be
tested; and there is affixed on the axis 6 the friction wheel f, the periphery of
which is turned true and smooth. On the friction wheel f is the friction band
h, which consists of a hoop of thin copper (24 in. by in.). To the interior
of this hoop h is fixed a lining of wood (preferring beech wood, the grain being
across the periphery), the pieces of which are fixed to the hoop h by wood
screws; and in order to keep the friction band h from shifting, the cross straps
are fixed to the band at intervals, as shewn; hence, when the friction wheel f
revolves within the friction band h, that band will remain correctly on the
periphery of the friction wheel f. On the friction strap h are fixed by screw
bolts, two plates k and l. The plate k is turned outwards at right angles at
its upper end, and a screw p passes freely through a hole in the turned out
portion of the plate k. On the screw p is a nut, by turning of which the
screw'p may be raised or lowered. The screw p is connected by a strap j (of
steel) to the beam e', e, which has its fulcrum fixed at d. The beam is not'
of equal length on both sides of its fulcrum, and although the relative pro-
portions may vary, it is found desirable that the end e' of the beam should be
about one sixty-fifth part of the whole length of the beam longer than the
end e. The other end e of the beam is connected to the plate l by a strap j
(of steel), as shown.
I would remark, that it is important thus to employ a beam or lever on a
fixed fulcrum in a dynamometer, so that the friction band may be attached to
the lever or beam at different distances from the fulcrum.
To the plate is attached, by means of steel straps m, the scale pan n.
According to the arrangement shown (which is suitable for testing engines
ranging between four and fourteen horse power), the circumference of the
apparatus is fifteen feet, measuring the circumscribing circle through half the
thickness of the straps j, j; hence, in using the apparatus to test the
power of
an engine, the stated power of the engine (that is, the number of horses power,)
is to be multiplied by 33,000, and the product is to be divided, the divisor

page_text: being the number of revolutions of the dynamometer multiplied by fifteen (the
circumference of the dynamometer), which will give the number of pounds
weight which is to be placed in the scale n; but as the weight of the scale pan
n and the excess of length of the beam are all on one side, there will require
to be an allowance (first to get equilibrium, and then for the difference of
leverage,) made in each case, and the latter allowance in respect to each
dynamometer will have to be ascertained in the following manner :-The screw
nut on p is to be perfectly slack, and supposing the smallest load the instru-
ment will ever be used with is thirty pounds, that weight is to be placed in the
scale, the friction wheelf being in motion; small weights are to be suspended
to the beam at o, and a like amount of weight is to be also added in the
scale n, and when the friction of the band is found to be sufficient to raise
the weighted scale n, the weight suspended at o is to be recorded. The instru-
ment is next to be tested with a load of forty pounds in like manner, and the
quantity suspended at o is to be recorded, and so on, till the instrument has
been tested for each ten pounds of load, from thirty pounds up to two hundred
pounds. A scale for the future use of the instrument is thus obtained. And
in the future using of the instrument, if one thirty-second part of the weight
which was placed at o for any particular load be placed in the scale at n, that
will be the equivalent in respect to the difference of leverage for obtaining
the requisite friction of the band for that load.
It should be stated that before testing an engine it is proper to slacken the
Ecrew nut on the screw p, so as to bring it to its lowest position, and then, when
all things are ready and the calculated weight plus the equivalent for obtaining
the friction has been placed in the scale n, the screw nut p is to be turned till
the rotations of the dynamometer raises the weight. From the above descrip-
tion, it will the evident that if the dimensions of the instrument be decreased or
increased, to render it suitable for less or large engines, the calculations will
be altered accordingly. If an engine continue to work, keeping the weighted
scale raised with the load, as above mentioned, it will be evident that the
power of the engine is equal to what has been stated to be its power; but
should the engine be unable to work when the scale n is weighted, as above
explained, then it would be evident that the engine was not of the power
stated; whilst, on the other hand, if the engine would work with a larger weight
or go faster with the calculated weight, then it would be evident that the power
of the engine was greater than that stated. The effect of the arrangement of
the apparatus shown is that it is self-regulating, and does not require any
person to be constantly regulating it; neither does it require to revolve in

page_text: soap and water, as has heretofore been commonly the case with some
dynamometers.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the precise details herein given and described; but what I claim is, the
mode herein described of combining the apparatus shown and explained.
In witness whereof, I, the said William Balk, have hereunto set my hand
and seal, this First day of January, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
Jxo. Cook,
12, Cursitor Street,
Chancery Lane.
WM BALK. (L.S.)