IMPROVEMENTS IN DYNAMOMETERS
Year: 1868

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," No. 8, Southampton Buildings, Chancery Lane,
in the County of Middlesex, Consulting Engineer, for the Inven-
tion of "IMPROVEMENTS IN DYNAMOMETERS."-A communication from
abroad by Charles Neer, of Brooklyn, New York, United States
of America
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition, on
the 2nd May 1868.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
No. 8, Southampton Buildings, Chancery Lane, in the County of Mid-
dlesex, Consulting Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN DYNAMOMETERS," a communication, to be
as follows:-
Dynamometers have heretofore been constructed with a view to
determine the strain or power exerted either to draw or to rotate any
given article, but it has been very difficult to calculate in the case

page_text: of revolving mechanism the power consumed, because the extent of
movement or distance travelled becomes an element in the calculation
based upon the actual force exerted.
The nature of my Invention consists chiefly in the combination of a
peripheral power scale with a steelyard or other measure of actual force
whereby the power exerted can be measured with accuracy, and the
nominal horse power be determined by inspection and a calculation
based upon the number of revolutions, and in this apparatus there is
no liability of derangement of the parts by wear. The shaft to which
the power is applied is arranged in line with another shaft, the two
shafts being united by ordinary couplings. The bolts usually introduced
to connect the flanges of the coupling are removed in order that the
power applied to rotate the second shaft may be transmitted through my
apparatus from the first shaft. The peripheral-power scale consists of a
wheel, or segment of a wheel, whose circumference or circle described
thereby bears a given decimal proportion to one thousand feet, so that by
rotating an even number of ten or hundred times it will cause a point
on its perimeter to travel one thousand feet in order that the power may
be computed with facility. The said peripheral scale may be attached to
the coupling of the shafts, or to the side or hub of a wheel or pulley.
When it is attached to the said coupling I use a ring with columns and
set screws, and make the said ring and the peripheral scale in two parts,
which are connected together by screws so that they can be arranged
around the shafting without the necessity of taking the same down.
Adjacent to the peripheral scale is a steelyard carrier made in two pieces
attached to each other by bolts, so that the carrier may be placed around
the second shaft and secured thereto by set screws. The necessity of
removing the said shaft from its bearings for applying the dynamometer
is thus prevented. The bolts and screws are to be formed at their
points with a series of cylindrical steps, which enter a conical hole bored
in the shaft or coupling. From the face of the steelyard carrier project
bars, around which springs are placed. A moving steelyard head is
connected to the carrier by chains passing around rollers on the said
carrier, the ends of the chains being attached to the peripheral power
scale. A hanging frame is held in place by a ring fitting in a groove
in a collar which is divided in two parts, and is clamped around the
second shaft. This hanging frame is provided with a socket, through
which passes a rod having divisions to indicate the horse power, and a

page_text: fork at the end of this rod lies in a groove in the hub of the moving
steelyard head. Around the collar is a single screw thread or worm
taking into the teeth of a worm wheel and moving the same one tooth
at each revolution of the shaft. The worm wheel is connected with a
pinion which gives rotary motion to a dial. On this dial are one
hundred divisions, and the worm wheel and pinion should be such that
the dial will turn once in a minute when the shaft is running at the
speed contemplated for the dynamometer. The steelyard and divisions
on the indicating rod should be proportioned to the varying range of
power, and the amount of power exerted to drive the second shaft will
be indicated by the divisions on the said rod. The dial being pro-
portioned to make one revolution per minute, if upon timing it there is
found more than one revolution, then add to the horses' power indicated
on the rod the decimal of excess, and if less then subtract the decimal
from the horses' power indicated on the said rod.
When my apparatus is employed in testing friction I attach to the
second shaft a cylinder, and for convenience short shafts may be
mounted in a lathe. The cylinder is enclosed in boxes which are held
in a frame to the bed of the lathe, and are adjusted by screws so as to
take a correct bearing upon the said cylinder. One of these screws is
carried by a lever which is weighted.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Williamı
Robert Lake in the Great Seal Patent Office on the 1st December
1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," No. 8, South-
ampton Buildings, Chancery Lane, in the County of Middlesex, Con-
sulting Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of May, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence
that I, the said William Robert Lake, my executors, administrators, and
assigns, or such others as I, the said William Robert Lake, my executors,

page_text: 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 "IMPROVEMENTS IN DYNAMO-
METERS," upon the condition (amongst others) that I, the said William
Robert Lake, 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 seven calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Drawing making a part of this Specification:
Dynamometers have heretofore been constructed with a view to
determine the strain or power exerted either to draw or to rotate any
given article, but it has been very difficult to calculate in the case of
revolving mechanism the power consumed in nominal horses' power,
because the extent of movement or distance travelled becomes an
element in the calculation based upon the actual force exerted.
The nature of my said Invention consists chiefly in the combination
of a peripheral power scale combined with a steelyard or other measure
of actual force whereby the actual power exerted can be measured with
accuracy and the nominal horses' power be determined by inspection
and a calculation based upon the number of revolutions, and in this
apparatus there is no liability of derangement of the parts by wear.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation of my improved dynamometer and friction
tester; Figure 2 is a plan of the said dynamometer; Figure 3 is an end
view of the perimetral power scale; Figure 4 is a section on the line x, x,
Figure 1; Figure 5 is an end view of the friction tester; Figure 6 is a
detached portion of my Invention drawn to an enlarged scale. Similar
marks of reference denote the same parts.

page_text: The power is applied to the shaft a; b is a separate shaft on the same
line; c and d are ordinary couplings employed to connect the shafts a
and b. In this case the bolts usually introduced to connect the flanges
of the coupling are removed in order that the power applied to rotate the
shaft b may pass through my apparatus from the motor a.
The peripheral power scale consists of a wheel e or segment of a wheel
whose circumference (or circle described by it) bears a given decimal
proportion to one thousand feet, so that its rotation, an even number of
ten or hundred times, shall cause a point on the said perimeter to travel
one thousand feet in order that the power may be computed with
facility, as hereafter shewn. The peripheral scale e is attached to the
coupling c, or in many cases it may more easily be attached to the side or
hub of a wheel or pulley. I have shewn the said peripheral scale e
attached by the columns 1, ring 2, and set screws 3 to the said
coupling c, and I make the ring 2 and peripheral scale e in two parts
connected together by screws 4, so that they can be attached around the
shafting without the necessity of taking the shafting down. Adjacent to
the peripheral scale e is the steelyard carrier f, made in two pieces
secured together by screws or bolts 5, so that it may be placed
around the shaft b, and secured thereto by set screws 6 to prevent the
necessity of removing the shaft from its bearings for applying the
dynamometer. The set screws 6 and the screws 3 are formed at their
points, as seen in Figure 6, with a series of cylindrical steps or shoulders,
which entering the conical hole bored in the shaft or coupling form a
secure attachment. The action of the power is therefore not to drive out
the screw and break the hub or wheel, as is the case with the conical or
inclined points, because the edges of the cylindrical steps imbed them-
selves in the metal at the bottom of the conical hole. By this means I
avoid difficulties heretofore experienced arising from injury to the parts
carrying the screw when under heavy strain. From the face of the
steelyard carrier f project bars 12, around which the springs 9 are
placed, and h is the moving steelyard head connected by chains i passing
around rollers k on the carrier f; the ends of the chains i are attached
to the peripheral power scale e. A hanging frame is held in place by
a ring in a groove in the collar m, which collar is divided for con-
venience of application around the shaft b, to which it is clamped by the
screws 7. Through a socket 8 on the frame passes a rod having
divisions to indicate the horse power, and a fork o at the end of this
rod n fits within a groove in the hub of the moving steelyard head h.

page_text: Around the collar m is a single screw thread or worm taking into the
teeth of the wheel p and moving them one tooth forward at each revolution
of the shaft b. q is a dial driven by the pinion 9. On the dial q are one
hundred divisions, and the wheel p and pinion 9 are to be such that the
wheel q will turn once in a minute when the shaft 6 is running at the
speed contemplated for the dynamometer. Suppose, for example, that
the peripheral scale e is of such a size that with four hundred and fifty
turns per minute a point thereon would travel one thousand feet, and
that the strength of the steelyard was such that it required thirty-three
pounds to draw the rod n through the socket 8 to the first point or
division, then the power indicated would be 1,000 feet travel × 33 lbs. =
33,000 lbs. raised one foot or a nominal horse power. The steelyard
and divisions on n are to be proportioned to the varying range of power,
and the amount of power exerted to drive the shaft 6 will be indicated
by the divisions on the rod n. If from any cause the speed of the
shaft 6 should vary from that contemplated for the dynamometer, the
dial q enables me to determine the difference of power resulting from
the increased or decreased speed. The dial being proportioned to make
one revolution per minute, if upon timing it there is found more than
one revolution, then add to the horses' power indicated on n the decimal
of excess, and if less then subtract the decimal from the horses' power
indicated on n. This dynamometer being constructed of a size adapted
to a given range of power, and the dial q accompanying it being geared
to indicate the contemplated speed for the horses' power marked on the
rod n, the actual power consumed under any speed or strain within the
capacity of the apparatus is determined by adding to or subtracting from
the horses' power indicated on n according to the speed denoted by the
dial q.
In order to employ my apparatus in testing friction I attach to
the shaft ba cylinder r, and for convenience short shafts may be
mounted in a lathe. The boxes 8 and t are held in a frame u secured to
the bed of the lathe, and the boxes 8 and t are adjusted by screws 10
and 11, so as to take a correct bearing upon the cylinder r, and the
lever which carries the screw 10 is to be weighted. It will now
be understood that the friction produced by running the cylinder r
within the boxes & and t may be actually measured by the power
indicated upon the dynamometer, and the decrease of friction by oils
and the various properties of lubricating materials or of composition ;
boxes or bearings can be accurately tested so as to determine the best

page_text: lubricating material, the best composition for lining the bearings, and
the frequency of lubrication.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and shewn how the same may be
conveniently and advantageously carried into practice, I claim,―
First. The peripheral power scale e in combination with the chains i,
and a steelyard or other measure of actual force, the parts being
constructed and combined substantially as and for the purposes set forth.
Second. Constructing the steelyard carrier f in two parts, so as to
apply the dynamometer to a shaft without removing it from its bearings,
substantially as set forth.
Third. The ring 2 and columns 1 in combination with the peripheral
power scale e for connecting the same to the coupling c, substantially as
set forth.
Fourth. The power indicator n and fork o combined with the steelyard
head h for the purposes and substantially as set forth.
Fifth. The dial q employed to indicate the proportion of speed in
combination with the indicator n, so as to determine the actual power
consumed, substantially as set forth.
8,
Sixth. The friction tester consisting of the cylinder and boxes s, t,
in combination with the dynamometer, substantially as and for the
purposes set forth.
In witness whereof, I, the said William Robert Lake, have hereunto
set my hand and seal, this First day of December, in the year of
our Lord One thousand eight hundred and sixty-eight.
WILLIAM ROBERT LAKE. (L.S.)
Witness,
THO. N. PALMER,
Clerk to Messrs. Haseltine, Lake, & Co.,
8, Southampton Buildings,
W.C.