AN IMPROVED DYNAMOMETER
Year: 1884

page_text: I RAPHAEL HUNTER BRANDON of 1 rue Laffitte Paris, France, and 114ª Queen
Victoria Street E.C. London, Engineer and Patent Agent do hereby declare the
nature of this Invention for AN IMPROVED DYNAMOMETER, 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 a dynamometer, which is an instrument for measuring
the amount of power taken from a driving pulley or other driving gear.
The Invention consists in a new combination of certain spring levers with the
pulley or wheel of the dynamometer, whereby the operation of the actuating pulley
or gearing is equalized in its effect upon the registering mechanism.
The Invention also consists in sundry details of improvement that are hereinafter
more fully specified.
Fig. 1 is a face view of the improved dynamometer, showing its general plan of
construction, but without certain attachments thereon that are shown in several
Figures.
Fig. 2 is a reversed face view, partly in section, of the construction shown' in
Fig. 1.
Fig. 3 is a central section of the disk that is placed against the supply coil of
registering-tape.
Fig. 4 is a face view of that disk.
Fig. 5. is a vertical section, taken on the plane of the line c, c; Fig. 6, of the
completed apparatus.
Fig. 6 is a face view of the apparatus completed, with the exception of the actuating
levers.
Fig. 7 is a face view of the completed apparatus.
Fig. 8 is a face view, partly in section; of the spool for receiving the registering
tape.
Fig. 9 is a vertical section of the pencil holder.
Fig. 10 is an elevation of the same, and,
Fig. 11 a detail plan view of the lever, which, in the construction" shown"
Figs. 6 & 7, causes the registering tape to move,

page_text: In the accompanying Drawings, the letter A represents the shaft upon which the
dynamometer is mounted and around which the pulley B, which is indicated by
dotted lines in Figs. 1 & 5 revolves; said pulley being mounted upon another shaft,
not the shaft A, or hung loose upon the shaft A. Upon the shaft A is mounted
and to it is secured, by set screws a, or otherwise rigidly fastened, a wheel C which,
with its spokes or framing, constitutes the body of the dynamometer.
To the spokes of this wheel are pivoted, so far as the principle of the Invention
is concerned, which is more clearly shown in Fig. 1, by pins b, b, two levers D & E,
which are connected with certain, preferably flat, springs F, that-bear upon the
hub of the wheel C and tend to so swing the levers D E that their shorter arins
bear against certain pins d, which project from the spokes of the wheel C. From
the driving pulley B extend lugs e, which are shown by dotted lines in Figs. 1, into
contact with the short arms of the levers D, E.
The apparatus works on the principle, namely, that when the wheel B is turned
in the direction of the arrow which is shown in Fig. 1, the lugs e will bear against
the short arms of the levers DE, and will thereby carry the wheel C around with
it in the same direction, and the more power is taken from the shaft A, which is so
revolved by the wheel C,-or, in other words, the more resistance the wheel C
offers to its revolution, by the contact with the wheel B, the further will the short
arms of the levers D, E, be swung away from the pins d, while, when the resistance
is lessened, the levers D E will approach in the same ratio towards the pins d.
The motion thus imparted to the levers D E on their pivots is to be utilized,
according to the Invention, for recording, on a tape within the wheel C, the degree
of the resistance and thereby the extent of power actually absorbed. To this end
only one of the levers D'E is utilized for registering purposes and the other lever E
is used simply for balancing purposes as to resistance and also as to the weight of
the wheel C. In other words, if the lever D were used alone, the lug e, which
actuates it, would, in moving upwards meet with a greater resistance than in
moving downwards, as it has the weight of the lever D to overcome in moving
upwards, while said weight assists it in moving downwards. Hence, the registra-
tion would not be perfect during each revolution, while, by adding the lever E, the
registration is equalized during the entire revolution.
To a spoke or other part of the framing of the wheel C, is pivoted by a pin f,
Fig. 2, a small elbow lever G, of which one arm g extends through a slot or hole in
the long arm of the lever D, whilst the other arm h of the lever G carries a pencil
holder i, in which a pencil is held: This pencil holder i is more clearly shown in
Figs. 9 & 10, and is a tube, screwed or otherwise fastened into the arm of the
elbow lever G, and containing within it the pencil j that projects below the lower
end of said tube, and containing likewise, above said pencil, a sliding plug k, which
is pressed downwards upon the pencil by a spring 1, which spring enters through
vertical slots in the upper part of the tube i, as is also clearly shown in Fig. 2.
The spring tends to hold the pencil in contact with the registering tape H, and to
crowd it down as its point is being worn off. The registering tape H, which may
be of paper or other suitable fabric, is taken from small drum, m, that is loosely
hung upon a pin n, said pin projecting from the face of the framing of the wheel C
(see Fig. 2). From this coil the tape passes over a table-like support o, which is
a fixed attachment to the wheel C, to a bobbin or spool p, which is mounted upon a
short shaft q, that has its bearings in the framing of the wheel C: Upon the shaft q
is mounted a ratchet wheel r, into which engages a spring pawls, that is pivoted to
the lever D. A retaining pawl t also enters the teeth of the wheel'r.
1.
It follows that as the apparatus, which has thus far been described with reference
to Figs. 1 & 2, is put in motion, the lever D, whenever greater power is applied
will be swung on its pivot b, so as to push the pawls over one or more of the
teeth of the wheel r, and, after the excess of power, that causes such a motion of
the lever D, ceases, the spring F will bring the lever D back towards, its, normal
position and will thereby cause the pawls to turn the wheel r, thus, winding the
registering tape further upon the spool p. Thus, the paper can be moved ahead
1

page_text: from time to time under the influence of the varying degrees of power that are
absorbed by the shaft A. At the same time, whenever the lever D moves, the
lever G, carrying the pencil, is also moved so as to cause the pencil to traverse the
face of the registering tape, thus making a mark which indicates the extent of
the power that had been absorbed at each period intervening between a motion of
the registering paper.
As far as described, it will be seen that the registering tape is not moved with a
degree of speed that bears any relation to the rotations of the wheel C, and the
mechanism so far described is of advantage only for showing, during a given period
of time, how frequently variations in the power taken up by the shaft A have
taken place and the extent of each variation. But, in order to apply this instru-
ment to the chronological measuring of power, and to ascertain, by its movements,
not only the extent of the variation, but also the period of time during which it
takes place, the attachment shown in Figs. 5, 6 & 7 may be employed.
These attachments consists substantially in means for moving the paper a certain
distance during every revolution of the wheel C. To this end, the framing of the
wheel C is provided, within its rim, with an annular flange u, which at one place
has a notch or recess v, cut out of it, said notch or recess being clearly indicated in
Figs. 6 & 7. Around this annular flange u is placed a loose ring I of larger internal
diameter than the external diameter of the flange u, so that normally, this ring will
have the tendency to lie on the flange, in the manner indicated in Fig. 5. To the
framing of the wheel C is pivoted a lever J (see Fig. 11) from which a pin w
projects at one side so as to be in contact with the inner periphery of the loose
ring I. The lever J also carries the pawls which gears into the ratchet wheel r.
In this construction, it will be perceived that the pawl s is no longer attached to
the lever D, Fig. 1. When the wheel C revolves, the pin w will, whenever it
arrives vertically above the axis of the shaft A, drop under the influence of the
loosely suspended ring-weight I into the notch or recess, v, as in Fig. 6, but when,
or after half a revolution of the wheel C, the pin w arrives vertically beneath the
axis of the shaft A, it will find below it a space sufficiently large intervening
between the flange ų and ring I, to enable it to drop out of the notch v and will be
drawn out of that notch, at that time by the spring x with which the lever J is
connected. The power of the weight I to press the pin w into the notch v in the
position of parts shown in Fig. 6 exceeds the counteracting power of the spring x.
Whenever the pin w, is, by the force of the spring x, pulled out of the notch in the
flange u, it is moved further away from the axis of the shaft A, the result being
that the lever J will carry the pawls one or more teeth, as may be pre-arranged,
over the teeth of the ratchet wheel r. And when the pin wis by the weight of
the ring I crowded back into the notch v, as in Fig. 6, said pin is thereby moved
nearer to the axis of the shaft A, and with it the lever J, the result being that the
pawl 8 will now turn the ratchet wheel to the extent of the play given to the pawl.
Thus, is produced in the ratchet wheel intermittent rotary motion which will
harmonize with the rotation of the wheel C itself, and this motion can be utilized
to give a certain intermittent feed to the registering tape. The most convenient
arrangement for this purpose is a worm-wheel connection a² from the shaft of the
wheel r, to a transmitting shaft 62, thence by a ratchet worm d on shaft b, to a
ratchet wheel e² on a shaft f', which shaft f2, in this construction, carries the
spool pupon which the registering tape is wound. A spring n² bears on the
shaft b, as in Fig. 6, and holds it in contact with the wheel e². When for any
reason, the ratchet wheel e2 is to be turned back, the shaft 6 can be raised off it,
against the spring n² until the wheel e' has been turned back as far as described.
It will be seen that by the construction shown in Fig. 6, the tape no longer is
wound directly upon the shaft of the ratchet wheel r, as in the construction shown
in Figs. 1 & 2, but is wound upon a shaft f² which gears into the shaft of the
ratchet wheel r. The elbow lever G, with its pencil holder i remains the same in
both constructions, but in the construction shown in Fig. 6, the advantage is gained,
1.

page_text: for some uses of dynamometers, of recording, owing to the uniform motion of the
paper; with reference to the motion of the wheel C, independent of the variation in
the degree of power taken, the time which transpired during the consumption of
any given amount of power that was absorbed by the shaft A.
The spool p for. receiving the registering tape H is more clearly shown in Fig. S
and is provided on its outer periphery with a curved spring g² of which one end is
rivetted or otherwise fastened to the circumference of the spool p, while the other
loose end bears, by the pressure of said spring, against the circumference of the
spool. From this spring extends a pin 2 through an aperture in the rim of the
spool, into the interior thereof. Whenever a new registering tape is to be applied,
the attendant pushes against the end of this pin h² and thereby lifts the free
end of the spring g² off the spool, making room for inserting the end of the
tape H, which, upon releasing the pin 2 will now be clamped to the spool by the
spring g with sufficient force to enable it to be properly retained by said spool
and carried around with it in manner described.
The drum m, which is loose on the pin n (see Fig. 2) is prevented from turning
spontaneously by a, spring 2 (see Figs. 3 & 4) which is affixed to the disk-shaped
cover that is placed over the box k² in which the coil H is contained. This spring i²
carries a plug which passes through the center of the disk j2 and bears against
the end of the drum m, so as to retain it in place sufficiently to prevent spontaneous
displacement without preventing it from turning under the influence of the ratchet-
action that feeds the tape, substantially as herein before described.
In order to vary the action of the lever D with reference to varying degrees of
power to which the instrument may be adjusted, this Invention contains means for
shifting its fulcrum and thereby lengthening or shortening its shorter arm, so that,
as this arm gets shorter more power will be needed to move the lever D against the
resistance of the spring F than is needed when the said arm is lengthened. This
arrangement for regulating the position of the fulcrum is shown in Figs. 6 & 7 and
consists in rigidly attaching to the spokes or other part of the framing of the
wheel C, for each of the levers D E a notched or grooved projection m², which is clearly
shown in Fig. 6, and in combining therewith a movable plate J having series of
teeth on one side that correspond with the notches or grooves in the projection m²,
and one tooth n² on the other side. The lever D, and also the lever E, of course,
for both must be adjusted alike, has several notches o² for receiving in one of them
the projection or tooth n². The plate J2 is slotted to receive and be movable on the
pin 6, all as shown in Fig. 7. Now, in order to change the fulcrum of the lever D,
from the position shown in Fig. 7, it is only necessary to shift the plate J² to the
right or to the left, as to its engagement with the projection m² and thereby carry
its tooth n² into another notch of the lever D. If the plate J2 is shifted nearer to
the axis of the shaft A, it will engage into the notch of the lever D, which nearest
to said shaft and will thereby make the short arm of the lever D longer, the
tooth 2 constituting the fulcrum of said. lever. If the plate J' is shifted towards
the periphery of the wheel C, the short arm of the lever D will be made
shorter..
In order to facilitate the attachment of this apparatus to a shaft that has already
been hung, without requiring such shaft to be taken off its bearings, the dynamometer
wheel C is constructed in two halves, as clearly shown in Fig. 6, which halves are
joined after they have been applied to the shaft by suitable bolts. This enables the
dynamometer to be fastened to any shaft without disturbing the latter.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The combination of the dynamometer wheel C with the lever D and mechanism
substantially as described, for recording the movements of the lever D on a tape,
and with the lever E and the lugs e, e on the actuating pulley B; all arranged for
the purpose of balancing the apparatus, substantially as specified.

page_text: 2. The combination of the dynamometer wheel C with the two levers D E and the
two springs F. F and with the actuating wheel B and its lugs e, e that bear against
both of said levers, substantially as described.
3. The combination of the dynamometer wheel C, having annular flange u and
notch therein, with the loose ring I, lever J, having pin w, pawls and ratchet
wheel r, all arranged for converting the continuous rotation of the wheel C into
intermittent rotation of the ratchet wheel r, substantially as described.
4. The combination of the dynamometer wheel C, having notched flange u, with
the ring I, lever J, pin w, spring ¤, pawl 8, ratchet wheel r, intermediate gearing
a², b², d² and shaft f, upon which the registering tape is wound, substantially as
specified.
.
5. The combination of the dynamometer wheel C, having notched flange u, with
the loose ring I, lever J, having pin w, pawl s, ratchet wheel ", spool p and
mechanism substantially as described, for conveying the motion of said ratchet
wheel r to the spool p, and with the lever D, elbow lever G, pencil holder i and
spring F, substantially as herein shown and described.
6. The slotted pencil holder i, combined with the plug or slide k, sustaining
lever G and spring 1, substantially as described.
7. The spool p combined with the spring g' and pin h² for the purpose of clamping
the end of the tape H, substantially as specified.
8. The combination of the box k and drum m contained therein, with the coverj³,
spring and plug 12, substantially as described.
9. The combination of the dynamometer wheel C, having toothed projection m²,
with the slotted plate J2, having series of teeth on one side and one tooth n² on the
other side, and with the lever D having notches wherein to receive the tooth n³,
substantially as described.
10. The dynamometer wheel C, made in two parts which can be fastened on to
a shaft already hung, in combination with the connecting bolts p², substantially as
specified.