IMPROVEMENTS IN DYNAMOMETERS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, ANDREW WILSON, Attorney and Counsellor at Law, of No 154 Nassau Street,
New York City, New York, United States of America, a citizen of the United
States of America, do hereby declare the nature of my Invention for "IMPROVEMENTS
IN DYNAMOMETERS," and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My Invention relates to rotary dynamometers, which register without diminishing
the power, and consists in machinery for reducing the power exerted and the speed
to a common unit of measurement, and making a record thereof upon a set of
indices, so that any one can in a moment determine the amount of power taken off
from the dynamometer.
My Invention also relates to means whereby the same dynamometer may be
adjusted to record with exactness, greatly divergent degrees of power:
.
In the Drawings:
Figure 1. is a plan view of my dynamometer.
Figure 2. is a view of a section of the same, taken on the line UV of Figure 4,
showing the ratchet wheel, and oscillating rotation and power recording arm.
Figure 3. is the side of the case or frame, showing the guide slots.
Figure 4. is a vertical cross sectional view, taken on the line X 2 of Figure 1.
Figure 5. is a view of the driving arm and slide rod and stop.
Figure 6. is a diagram showing the method of locating the guide slots.
Similar letters of reference designate similar parts in all the Drawings.
A is a loose pulley on the shaft C-B is an arm bolted together and rigidly keyed
to the shaft C.
Through the end of the arm B passes the bolt E. The two ends of the arm B
may be duplicates, and two bolts E with their springs and connections may be
used to distribute and equalize the strain, if desired.
One end of the bolt E, is secured to the lug D in the pulley A, so that it may
oscillate but not escape and the other end passes loosely through a hole in the end
of the arm B, and is held in place by the nut d'. F is a spiral spring through
which passes the bolt E; one end of the spring F rests against the nut d³ on the
bolt E, and the other end rests against the washer e, which slides loosely upon
the bolt E and receives the pressure of the arin B. The tension and position of the

page_text: spring. may be readily and accurately reguinted by means of the nuts a a—11
power be applied to the shaft and resistance to the pulley, the spring F will be
compressed between the arm B and nut d³, the degree of compression varying
with the power exerted.
M is a rod attached to the arm B, the centre line of which coincides with a radius
of the pulley and shaft. On this rod M is the slide N, which slide can move
upward and downward upon the rod M, but not turn thereupon. R is an arm
pivoted at t to the frame or case formed by the sides or plates P P', which frame
or case is rigidly attached to the pulley A. The arm S is attached to the arm R,
and is connected at ở to the rod w, the end of which rod w will rise, when the
arm S is raised, above the surface of the pulley A. O is a spring attached at one
end to the pulley A, or case, and at the other end to the arm R. Qis a ratchet on
the arm R, which acts upon the ratchet wheel G. This ratchet wheel G carries the
pinion g, which turns the gear wheel H, which wheel H carries the pinion wheel h.
The pinion wheel h gears with the wheel I (Fig. 1). On the end of the shaft of
the wheel I is the pointer J. The wheel I carries the pinion wheel i engaging the
gear wheel J, and on the shaft of the wheel J' is another pointer J. The
pointer K is turned by a similar pinion wheel and gear wheel actuated by the gear
wheel J. If the pinion wheels have each ten cogs and the gear wheels have each
one hundred cogs except the wheel I which has sixty cogs, if the wheel a revolves
once a minute H will turn once in ten minutes, I, once in an hour, J³, once in ten
hours, and so on.
Additional indices may be added if desired.
The arm R is drawn forward by the spring o, until it comes in contact with the
point n of the slide N. When no power is being taken off the pulley the spring F
will not be compressed, and the point will hold the arm R back, so that the
rod w will not project beyond the face of the pulley A.
When the spring F is compressed, the slide N, moving with the rod M and
arm B, will be carried forward, allowing the spring O to draw forward the arm R
and raise the rod w above the surface of the wheel, and the ratchet Q will pass one
or more teeth of the wheel G, as the distance may be more or less. As the wheel
revolves the end of the rod w will come beneath the belt, and be pressed down
until it is level with the surface of the pulley, driving. back the arm R and by the
ratchet Q turning the wheel G the number of teeth passed by the ratchet on its
forward swing...
If the stop N was rigidly attached to the rod M, although the arm B moved
equal distances for each horse power applied, there would be a slight variation in
the number of teeth passed, as the power increased, because the point of contact
with the arm R would be constantly retreating from the pivotal point t, without
any corresponding compensation in the rod M.
To remedy this I use the guide slots.shown in Figure 3—1, 2, 3, 4, 5, 6, 7, 8; and
slots in the side P of the case or frame.
As shown in Fig. 6 the curve of these slots may be fixed by describing segments
of two circles a¹ and b' having respective centres & and the center g¹ of the shaft C,
and touching on their circuinference at the point m', from which the curve is to be
drawn. In each of these circles, on the same side of the point m of contact and
starting therefrom describe equal chords c¹ m¹ and c' m². Extend radii ď³ d' of
each circle through the end c' c³ of the chords c¹ m³, c² m² of their respective circles
farthest from the point of contact, until these radii meet. The point X³ at which
they intersect will be one of the points through which the curve must pass, and the
rest of its course may be determined by drawing other chords as e¹ m² e² m², s¹ m²
83 m² and extending other radii as w', w³ a'z³ in a similar manner. The curve of
each slot is different from that of the others and must be separately located (see
dotted lines, Figure 6).
The point of the slide N passes through one of these slots, for instance 1—
g represents a point on the arm R, and p a point opposite to it on the rod M,

page_text: D
When the stop N is at p, if the spring F is compressed and the arm B and rod M
moved forward, the slide N will move along in the slot 1, rising somewhat on the
rod M, above the point p, and always marking the point at which when the arm R
stops in its oscillations, by coming in contact with the point n, the point q on the
arm R will describe an arc the chord of which will be equal to the chord of the
arc described by the point p on the rod M, and consequently an accurate
ineasurement of the degree of compression of the spring F will be made by the
ratchet Q upon the wheel G.
If the pulley make one hundred revolutions per minute, and one horse power
compresses the spring F sufficiently to let the ratchet Q pass one tooth at every
oscillation of the arm R, the indices J, J' K will mark the number of hours this
power is exerted. If the distance be increased the ratchet will pass more teeth of
the wheel G, and the indices record more horse power hour units; or if the
revolutions be increased, the ratchet will pass the teeth more rapidly and the indices
record more horse power hour units; it being evident that the aggregate is the
same, whether the pulley deliver one horse power for five hours or five horse powers
for one hour, the result in either case being five horse power hour units.
If the power exerted is sufficient to pass several teeth on the wheel G at every
oscillation of the arm R it will be convenient to take the record from a lower
point on the rod M, where the vibrations are not so great.
If the point 1 is at one eighth of the distance from the center of the pivot t to
the center of the shaft C and the compression of the spring F is such as to allow
a certain number, for instance seven, of the teeth to be passed by the ratchet Q at
every oscillation of the arm R, the slide N being at 1, if the slide N be moved to
one seventh of the distance from t to the centre of the shaft C, as 2, with the same
compression of the spring F, the ratchet will pass six teeth.
If the slide be moved to ono sixth of the same distance, as 3, the ratchet will
pass five teeth; if it be moved to one fifth of the distance, as 4, four teeth; to one
fourth the distance, as 5, three teeth; to one third the distance, as 6, two teeth;
and if to one half the distance, but one tooth. With the slide at two thirds of the
distance the compression must be twice as great to allow one tooth to pass at three
quarters three times as great, and so on, so that at seven eighths of the distance the
compression of the spring F must be seven times as much to permit one tooth to
pass, and every tooth passed will represent seven horse power units.
When the dynamometer is adjusted to register with the slide N in a given slot,
then if the slide N be changed from that slot to another, the record of the indices
must be increased or diminished in the ratio above given, as the new slot may be
above or below the former one.
Thus if the dynamometer be set for slot 1 and the slide N be afterwards moved
to slot 7, each unit recorded on the indices will represent one seventh of the actual
number of units of horse powers exerted.
By swinging the arm B back until the point n of the slide N shall pass into the
alot 9, the slide can then be moved up or down on the rod M to any desired guide
slot. Any suitable stop may be used to prevent the arm B swinging back into
this position except when 'desired.
The nut d' will hold it firmly enough for most purposes, but if a lock is used,
also, no one can then alter the record of the dynamometer without injuring or
breaking its parts.
Any suitable mechanism that will cause the arm R to oscillate with regularity,
may be employed instead of the rod w and arm S, and I do not confine myself to
the devices shown for that purpose; and any mechanism may be employed which
will cause the rod M to mark with regularity the divergence, under the application
of power, of an extended radius of the shaft C, and a radius of the pulley A.
And I do not confine myself to the particular devices shown for that purpose,
5 nor to the particular arrangement of gear and index wheels, for the record may
be taken off of the ratchet wheel G by any suitable arrangement of gear wheels.

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this would produce more wear in the slots.
милии идили
Likewise the ratchet wheel G might be turned by the spring O, and the opposite
movement of the ratchet produced by the rod w.
Having now particularly described and ascortained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In a dynamometer the rod M and arm R adjusted so that oscillations of the
arm R shall be controlled by the rod M substantially as and for the purposes
.set forth.
2. In a dynamometer, a plate having a slot or slots adapted to regulate the
position of the slide N relative to the rod M and arm R, substantially as and for
the purposes set forth.
3. In a dynamometer, a plate having slots therein to regulate the position of
the slide N relative to the rod M and arm R, and having a slot by which the
slide N can be moved from one of said regulating slots to another, substantially as
set forth.
4. In a dynamometer, the combination of the rod M, slide N and a plate having
a slot or slots to regulate the position of the slide N, substantially as and for the
purposes set forth.
5. In a dynamometer, the combination of the arm R, rod M, slide N and a plate
having a slot or slots adapted to regulate the position of the slide N, substantially
as and for the purposes set forth.
6. The combination of the ratchet wheel C, ratchet Q, arm R, slide N, a plate
having a slot or slots, and rod M, substantially as and for the purposes set forth.
7. In a dynamometer the combination of the rod M, adapted to stop the arm R
in its oscillations, with the arm R, ratchet Q and ratchet wheel G, substantially as
and for the purposes set forth.
8. In a dynamometer, the combination of the rod M, adapted to stop the arm R
in its oscillations, with the arm R, ratchet Q and ratchet wheel G and intermediate
gear wheels adapted to transmit, and indices adapted to record rotations of said
wheel G, substantially as and for the purposes set forth.
9. The combination of the rod w, arm S, arm R, ratchet Q and ratchet wheel G,
spring O, slide N, regulated by a slot or its equivalent, rod M. arm B, and spring F,
substantially as and for the purposes set forth.
10. The combination of the rod w, arm S, arm R, ratchet Q, ratchet wheel G,
with gear wheels and indices to record the revolutions of the wheel G, spring O,.
slide N regulated by a slot or its equivalent, rod M, arın B and spring F, combined
and operating, substantially as and for the purposes set forth.
11. The combination of a swinging arm, means for oscillating the same to mark
revolutions of the dynamometer, a ratchet wheel with indices to record the length
and number of the oscillations of such arm in a common unit, and mechanism
adapted to lengthen or shorten the swing of such oscillating bar in the same
ratio as the power transmitted by the dynamometer is increased or diminished,
substantially as set forth.
12. The combination of mechanism indicating revolutions or speed of a rotary
dynamometer,, with mechanism indicating resistance or power, by which such
speed and power are reduced to a common unit of measurement, such mechanism
being carried upon a shaft, transmitting the power to be measured, and requiring
no connection or contact with anything but such shaft and the belt or its equivalent
.taking or delivering power from or to the shaft. :
13. A swinging or pivoted arm, in combination with means for oscillating the
same to mark revolutions of the dynamometer, and mechanism adapted to lengthen
or shorten the swing of such arm in the same ratio as the power transmitted by
the dynamometer is increased or. diminished, substantially as set forth.

page_text: 14. The rod M adapted to indicate with uniformity varying degrees of resistance
in the pulley A¹ by its divergence from a radius of such pulley, in combination
with mechanism for measuring and recording the extent of such divergence in a
common unit with the revolutions of such dynamometer, for the purposes set
forth.
15. In a dynamometer the combination of the pulley A, bolt E, nuts d', d³, arm B
and shaft O, substantially as and for the purposes set forth.