Year: 1886

page_text: I, JAMES EMERSON, of Willimansett, in the Town of Chicopee, in the County
of Hampden and Commonwealth of Massachusetts, one of the United States of
America, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
This invention relates to Dynamometers or Power Scales for ascertaining the
power required to drive a machine or machinery, and has for its object to make.
the dynamometer more convenient of manipulation and easier to be attached to the
shaft of a machine or to a line of shafting and capable of having its motion
reversed.
My improvements are shown in the accompanying drawings on two sheets in
which figure 1 is a front elevation of a dynamometer provided with my improve-
ment, and a speed indicator, a part of the dial of said indicator being broken away
to show how the indicator is driven; figure 2, a left end elevation of the same with
the movable parts in the same position as in figure 1; figure 3, a vertical, central
section of the same with the scale, pendulum, dash-pot and part of the dash-pot rod
omitted, the movable parts being in the same position as in figure 1; figure 4, a
vertical, central section, omitting the parts omitted in figure 3, and also the weight
and drum, the plane of the section of the movable parts being at right angles to
the plane of the section shown in figure 3 and on the line y y in figure 2; figure 5,
a side elevation of the hub-plate, on which the levers are fulcrumed, and the
carrying-plate to which the outer ends of the levers are pivoted, parts of said plates
being broken away to show the attachment of said levers; figure 6, a view of the
right side of the carrying-plate and the dog-plate which forms part of a clutch;
figure 7, a plan of the left end of the hub and the parts connected thereto, the
dotted lines showing the clutch lock open; figure 8, a plan of the clutch lock
detached, its holder being in horizontal, longitudinal section; figure 9, a front
elevation of a modified form of my improvement; figure 10, a left end elevation
of the same; figure 11 a section on the line in figure 9; figure 12, a front
elevation of another modified form of my improvement.
The frame A depending loosely from the hub B1, carries on a pivot below, the
forked bell crank lever A, the outer end of which is connected to the drum A* by
chains A³, and also carries dashpot.rod A' with dash pot A. The drum A³ carries

page_text: the swinging weight or pendulum A* with index finger a which measures the
A collar A
power on the graduated scale or quadrant A³ fixed to the frame As.
sliding loosely on the hub B¹ is in connection with the bell crank lever A¹ and
controls the latter.
The speed indicator C is of well known form and is driven substantially as
shown by a worm b on the hub B¹, of the hub-plate B. The hub-plate has a
central opening 6' in which is placed a chuck D or sleeve of steel, the inner surface
of which chuck is cylindrical, the outer surface of which, for a distance from its
right end, as shown at 6' in figures-3 and 4, is conically enlarged, and the opening
of the hub b¹ is correspondingly conically enlarged at its right end. The chuck or
sleeve D extends through the hub and projects therefrom at the left end thereof,
and is externally screw-threaded to engage a nut D¹, which being turned thereon
against the free end of the hub B¹ tends to draw the chuck through the hub to the
left. The chuck is slotted at d lengthwise so that when the conical part of the
chuck is drawn into the conical part of the opening 6' the diameter of that part of
the chuck is reduced which enables the instrument to be secured to a shaft of a
machine or to a line of shafting either of which may be indicated by the part
marked S in figure 1.
When the chuck is tightened on a shaft by turning up the nut D¹ against the
end of the hub, the chuck, hub and hub-plate will revolve with said shaft if the
latter be revolved, the scale, pendulum, dash-pot and speed indicator and other
parts supported on the bracket, not turning with said hub. The internal diameter
of the chuck is reduced at a slight distance from the closed end of the slots d to
form an annular shoulder d. Into the chuck between its large end and the
shoulder d¹ may be inserted a reducing chuck or steel sleeve slotted nearly from
end to end to enable a smaller shaft to be grasped.
Between ears 6 on the flange 63 of the hub-plate are pivoted the prime
levers LL, of which there are four arranged in two pairs, a pair on each side of
the hub, the levers of the same pair being in nearly a straight line with each other
and about parallel to the levers of the other pair.
The outer ends of the prime levers L L' reach into slots e in the flange e¹ of the
carrying-plate E, and one lever of each pair is pivoted to said flange e¹, as will be
explained below.
.It is sufficient to say here, that a movement of the hub-plate and carrying-plate,
with reference to each other will turn the prime levers on their fulcrums. The
inner ends of the prime levers of the same pair are pivoted to each other and to a
connecting rod M which runs about radially, and is pivoted to the short arm of a
bell crank lever N.
The last named lever N is pivoted at n, between ears 66 projecting from the
flange 63 of the hub-plate, and its long arm runs in radially towards the sliding
collar A and is pivoted at n¹ to one end of a link or short connecting rod, the other
end of which is connected to ears a¹ formed on the side of said collar. It will be
seen that an outward movement of the inner ends of the prime levers will cause
the collar A to slide towards the hub-plate raising the lower end of the forked
lever A¹ and unwinding the chain from the drum A to which the pendulum weight
is attached, swinging said pendulum towards the hub-plate and causing the index
finger to rise over the scale.
The carrying plate E is provided with a flange e¹ which surrounds the hub-plato
and has a slight movement around the same, resting on anti-friction rolls F which
are journalled in the flange b³ of the hub-plate parallel with the axis of the hub
and turn in slots be formed in the flange of said bubsplate. The carrying-plate E
is provided with a hub et on which turns the dog-plate G, said dog-plate being
provided with a hub 'g and being held on the hub of said carrying-plate by an
annular plate H secured to the end of the hub e² of said carrying-plate and covering
the end of the hub g of said dog-plate. The dog-plate G is provided with one or
more preferably two, sockets g¹ in which are inserted studs I which are intended
to pass between the arms of a pulley, as hereinafter described.

page_text: The dog-plate is also provided with radial projections or dogs g³, adapted to
strike a sliding pin P.(placed in a hole ed in the flange of the carrying-plate) when
the said pin projects from the face of the carrying-plate. The pin P is caused to
project from said carrying-plate. by sliding the tube T to the left, as shown in
figures 3 and 4, said tube T having an annular groove t into which reaches a pro-
jection on a slide U which lies in a longitudinal groove b7 in the hub B¹. The
other end of said slide U is provided with an outward projection u³ which has a
notch u³ to receive the rounded end of a lever V pivoted at v to ears be projecting
from the left side of the hub-plate. The outer end of the lever V is rounded and
enters a notch p in said pin P. Hence pushing the tube T into the hub draws the
pin P back out of reach of the dogs g on the dog-plate, and drawing said tube out
or to the left throws the pin P to the right where it may be struck by said dogs.
The tube T is held in either position by a lock consisting of a lever K which turns
on the bracket k secured to said frame A3 and is provided with a stud k¹, which
when said lever K is turned into the position shown by full lines in figure 7,
reaches by the edge of a flange t¹, with which said tube is provided, and prevents
the tube being drawn out of the hub and the pin P from engaging with the dogs
on the dog-plate, and on the other hand, when the tube is drawn out and the
stud k² is to the right of said flange t¹ (see dotted lines in figure 4) the pin P cannot
be drawn or accidentally shaken out of engagement with said dogs. The lock or
lever K is held in its locking position or at right angles thereto by a block k which
slides in a suitable opening or chamber k in said bracket, and is pushed by a spiral
spring against the flat end of said, lever K. when the same is locked and against.
the flat back of the same when unlocked (see figures 7 and 8).
The operation of the above described dynamometer, as applied to the shaft of a
machine or to a line of shafting is as follows:-
The instrument is attached to the shaft by the clutch as above described, and the
studs I are placed between the arms of the loose pulley (care being taken that the
two studs I, bear equally against two opposite arms of such pulley, or equally in
two diametrically opposite holes drilled in the web of a plate pulley), said pulley
and shaft being at this time at rest, and the sliding pin P being out of engagement
with the dogs of the dog-plate. The belt is then placed on the loose pulley, and
shifted thence to the fast pulley, causing the latter to rotate and with it the shaft,
the hub, the hub-plate, the levers pivoted thereon, the carrying-plate and the dog-
plate, the latter being rotated by the friction between it and the carrying-plate,
and thereupon the connected ends of the prime levers L L¹ will be thrown outward
slightly from the hub by centrifugal force and will cause the sliding collar A to
move on the hub towards the hub-plate and through the connecting mechanism
above described, will cause the pendulum to move upward over the arc or graduated
scale A³ and the index finger a to indicate on said scale the tare of number of
pounds exerted by centrifugal force.
The belt is then run very gradually on to the loose pulley, but not entirely off
from the fast pulley. When both the fast and loose pulleys have attained an equal
speed of rotation the sliding pin is pushed to the right by the means above described
to be ready to engage with the dog of the dog-plate. But inasmuch as the sliding
pin P, at the time when it is pushed out to the right may be at some distance from
either of the dogs on the dog plate, and would be likely to be broken by a violent
blow from one of said dogs, the belt is moved very gradually from the fast to the
loose pulley. No weighing of the power takes place when the belt is wholly
or partly on the fast pulley, said weighing being accomplished by driving the.
dynamometer through the medium of the loose pulley and the dog-plate and
its studs.
When the belt is entirely shifted from the fast pulley to the loose pulley, the
dog-plate being caused to revolve by the loose pulley causes the carrying plate
to revolve with it, by the dog of the dog-plate pressing against the sliding pin, P.
The revolution of the carrying-plate and the inertia of the hub-plate cause the
prime levers to turn, upon their fulcrums and to throw their inner end outward

page_text: from the hub and this causes the collar A to slide on the hub towards the hub-
plate and the pendulum weight to swing to the right, and the index finger to
indicate on the scale the number of pounds of force exerted.
The number of revolutions of the shaft for one minute is ascertained in the usual
manner by the speed indicator C.
The tare is now deducted from the number of pounds indicated while the belt
was on the loose pulley, and the remainder is multiplied by the number of feet
in the circumference of the circle described in a single complete revolution of one
of the bearing pivots which connect the outer end of a prime lever with the
carrying-plate. By then multiplying this product by the number of revolutions
in a minute and dividing this last product by 33,000. the number of horse power
will be shown by the quotient.
In the modification shown in figures 9-12 of the drawings the dash-pot rod and
the forked bell-crank lever lie in the same vertical plane instead of being in.
different planes, as shown in figure 2.
Arranging the dash-pot rod and said lever last named in the same vertical plane
renders said. lever less liable to be twisted and to wear unequally upon its fulcrum,
and allows said lever to move with greater freedom.
In figures 9 and 12 the forked lever A¹ is provided with a counterpoise W W
which is supported in each case upon an extension of said lever, the counterpoise
in one case (figure 9) being supported in an obvious manner and in the other case.
(figure 12) consisting of a ball provided with a screw-threaded hole which engages
a thread .cut on the extension of said lever A¹. In both of the figures last named.
the removable weights on the dash-pot rod instead of being placed over the top
of the rod are slotted to the centre in order that they may be placed ou said rod
below where it is pivoted to the lever A¹. This arrangement tends to make the
movement of said lever A¹ steadier. In figure 12 the pendulum weight is dispensed
with and the long arm of the lever A² is notched and graduated like the long arm
of an ordinary steelyard and a weight a, provided with a hook, is moved along
said long arm by hand just as the weight of a steel yard is, and the part of the
frame As which in the other figures is shown to be provided with a scale serves
merely to support a rod A³, the upper end of which is bent horizontally and
pointed in the line of the axis of the lever A¹ when the same is in a horizontal
position. In figure 12, the free end of the long arm of the lever A¹ is pointed and
when this pointed end is in the same straight horizontal line with the point on the
rod A, the power and the weight balance each other.
Having now fully described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what.
I claim is ;-
1. The combination in a dynamometer or power scale, of a hub-plate or frame
adapted to be secured to a shaft and to rotate therewith, prime levers having their
fulcrums on said hub-plate, a carrying-plate having a hub and having a flange.
or ring supported and bearing upon rolls turning in said hub-plate, a dog-plate
turning upon the hub of said carrying-plate and adapted to be engaged with the
loose pulley, on said shaft and having one or more dogs, and a pin sliding in said
carrying-plate and adapted at will to be thrown into or out of engagement with
a dog of said dog-plate, to enable the rotation of the hub-plate and carrying-plate
to be started and stopped without stopping said loose pulley, substantially as
described.
2. The combination of the hub-plate or frame adapted to be secured to the sbaft
and to be revolved therewith, said hub-plate being provided with a hub, having
a longitudinal groove and a slot leading from the end of said groove into said
hub, prime levers having their fulcrums on said hub-plate, and having their outer
ends pivoted to the currying-plate, said carrying-plate provided with a flange and
with a hub and concentric with said hub-plate, a dog-plate provided with one or
more dogs, and, turning upon, the hub of said carrying-plate, and adapted to be.

page_text: connected with a loose pulley on said shaft and to be rotated by said loose pulley,
a pin sliding in the flange of said carrying-plate, a tube adapted to slide in said
hub and provided with an annular groove, a slide arranged within said longitudinal
groove and having a projection adapted to reach through said slot and into said
annular groove, a lever having its fulcrum on said hub-plate and engaging at
one end with said slide and at the other with said sliding pin, to throw said
pin into or out of engagement with said dog-plate, substantially as described.
3. In a dynamometer, the combination of a hub-plate, provided with a hub and
having a central bore for a portion of its length flaring outwardly, and a chuck
longer than said hub and conically enlarged for a part of its length, and provided
with longitudinal slots and placed within said bore, the small end of said chuck
projecting from said hub and having an external screw-thread, a nut engaging
said screw-thread and turning against the end of said hub, to contract said
chuck and thereby to secure said hub-plate to a shaft, as and for the purpose
specified.
4. The combination in a dynamometer of a hub-plate adapted to be secured
to a shaft and to revolve therewith, prime-levers having their fulcrums upon said
hub-plate, and a carrying-plate turning freely upon said hub plate, said prime
levers being pivoted at their outer ends to said carrying-plate, as and for the
purpose specified.
5. The combination in a dynamometer or power scale of a hub-plate or frame,
adapted to be secured to a shaft and to revolve therewith, two pairs of prime
levers having their fulcrums upon the said hub-plate or frame, a carrying-plate
provided with a flange one lever of each pair of prime levers being pivoted at its
outer end to said flange, by a removable pivot, adapted to connect the outer lever
of the same pair to said flange when the direction of motion is reversed, as and for
the purpose specified.
6. The combination in a dynamometer of a hub-plate adapted to be secured to
a shaft and to revolve therewith, a carrying plate turning freely on said hub-plate,
two pairs of prime levers having their fulcrums upon said hub-plate, the inner end
of each pair of prime levers being connected to each other, and to the inner end
of a connecting rod, said connecting rod connected at its outer end to the short
end of a bell crank lever, the other or inner end of said bell crank lever being
connected to a link, a collar connected to said link and sliding on said hub, a forked
lever pivoted to said sliding collar, a stationary frame depending from said. hub,
a pendulum weight provided with an index finger, and with a drum, a chaia
connecting said drum and the outer end of said last named lever, a graduated scale
supported by said stationary frame, one lever of each pair of prime levers being
pivoted by a removable pivot to the flange of said carrying-plate and said pivot
being adapted to connect the other lever of the same pair to said flange when the
direction of motion is reversed, as and for the purpose specified.
7. The combination of the hub-plate or frame adapted to be secured to a shaft,
and to be revolved therewith said hub-plate being provided with a hub, having
a longitudinal groove and a slot leading from the end of said groove into said hub,
prime levers having their fulcrums on said hub-plate, and having their outer ends
pivoted to the carrying-plate, said carrying-plate provided with a flange and with
a hub and concentric with said hub-plate, a dog-plate provided with one or more
dogs, and turning upon the hub of said carrying-plate, and adapted to be con-
nected with a loose pulley on said shaft, and to be rotated by said loose pulley,
a pin sliding in the flange of said carrying-plate, a tube adapted to slide in said
hub and projecting therefrom, and provided with an annular flange outside of said
bub, and with an annular groove within said hub, a slide arranged within said
longitudinal groove, and having a projection adapted to reach through said slot
and into said annular groove, a lever having its fulcrum on said hub-plate, and
engaging at one end with said slide and at the other with said sliding pin, a
stationary frame or bracket depending from the hub of said hub-plate, a lever or
lock provided with a pin and pivoted to said stationary frame, and adapted to

page_text: hold said last named pin in engagement with and on either side of the flange of
said sliding tube, and to hold said sliding pin either in or out of engagement with
said dog-plate, as and for the purpose specified.
In witness whereof. I, the said James Emerson, have hereunto set my hand
and seal this twenty-ninth day of July A.D. 1885.