Improvements in Dynamometers.
Year: 1899

page_text: Date of Application, 7th Apr.,
1899
Complete Specification Left, 6th Jan., 1900-Accepted, 17th Mar., 1900
Improvements in Dynamometers.
I, GEORGE JAMES GIBBS, of Water Lane Works, Bradford, Yorkshire, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to the construction of that class of dynamometers known
as transmission dynamometers in such a manner that a record of the amount of
force, or power, transmitted through the apparatus is permanently registered.
Several attempts have been made to construct an apparatus which will indicate
on an index, or scale, the power transmitted at any given moment, with more
or less success but up to the present so far as I am aware no transmission dyna,
mometer has been made which will give a definite, accurate, and permanent
record of the amount of power transmitted by a revolving shaft.
The difficulty
has been that owing to the revolution and vibration of the apparatus, it has not
been possible to read accurately on a scale, or otherwise, the amount of force
or power indicated as passing through the dynamometer, and consequently the
results obtained have not been reliable.
Now the object of my invention is to produce a dynamometer which will
accurately measure and record the amount of force being transmitted, in such a
form that the result may easily and at leisure, be read off, either as units of
force, or taking a time factor into consideration as units of power, and which
especially shall be so accurate as to enable power to be measured and sold by
meter in much the same way as gas, water, or electricity.
My invention is applicable mainly to that form of dynamometer which consists
of one or more levers fixed to a revolving shaft, and connected by means of
springs to a pulley working on the same shaft and revolving with it. The springs
are in compression or tension according to the angular position of the levers
with respect to the arms of the pulley to which the springs are attached, and in
the case of a regular force the springs may be arranged to be either in tension
or under compression, according as I find most suitable to each case. The whole
of the force is passed through the springs which are compressed or extended_in
proportion to the amount of the force transmitted at any given moment. By
means of my invention I can record this varying compression or extension of the
springs and so obtain a measure of the force passing through them at any time.
I do this by attaching to the pulley a small drum rotated either by means of
a clock work mechanism or by means of suitable gearing whereby the revolution
of the apparatus itself causes the drum to revolve. I also provide suitable means
for starting and stopping the motion of the drum as required.
This drum is provided with paper upon which works an index pointer or pencil
connected by any suitable means to the springs above mentioned so that any
movement of compression or extension in the springs will make a corresponding
mark on the paper, and by using a suitable scale and calibrating the instrument,
an accurate record is obtained on the paper of the amount of force transmitted.
It must be understood that I may use two or more drums, winding the paper
from one to the other, if it is required to cover a long time of working.

page_text: Also I may so arrange that by means of a dial, and integrating apparatus such
as is used in planimeters or otherwise, the amount of work transmitted by the
dynamometer can be read off directly without further calculation I may also
arrange that the integrating mechanism can be started and stopped at any time
whether the pulley is revolving or not.
Dated this 7th day of April 1899
SYDNEY E. PAGE, A.M.I.C.E.,
18, New Bridge Street, London, E.C., Agent for the Applicant."
Improvements in Dynamometers me 3.37
I, GEORGE JAMES GIBBS, of Water Lane Works, Bradford, in the County of
York, 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 the construction of that class of dynamometer known
as transmission dynamometers in such a manner that a record of the amount of
force or power transmitted through the apparatus is permanently registered.
Several attempts have been made to construct an apparatus which will indicate
on an index, or scale, the force transmitted at any given moment, with more
or less success, but up to the present so far as I am aware no transmission dyna-
mometer has been made which will give a definite, accurate, and permanent
record of the amount of force transmitted by a revolving shaft. The difficulty
has been that owing to the revolution and vibration of the apparatus, it has not
been possible to read accurately on a scale or otherwise, the amount of force
or power indicated as passing through the dynamometer, and consequently the
results obtained have not been reliable.
Now the object of my invention is to produce a dynamometer which will
accurately measure and record the amount of force being transmitted, in such a
form that the result may easily and at leisure, be read off, either as units of
force, or taking a time factor into consideration as units of power, and which
especially shall be so accurate as to enable power to be measured and sold by
meter in much the same way as gas, water, or electricity.
My invention is applicable mainly to that form of dynamometer which consists
of one or more levers, or of a disc, fixed to a revolving shaft and connected by
means of springs to a pulley working on the same shaft, but not rigidly attached
to it. The springs are in compression or tension according to the angular posi-
tion of the levers or disc with respect to the pulley, and in the case of a regular
force they may be arranged to be either in tension or under compression according
as it is found most suitable for each case. The whole of the force is passed
through the springs which are compressed or extended in proportion to the
amount of force transmitted at any given moment.
By means of my invention I can record this varying compression or extension
of the springs and so obtain a measure of the force passing through them at any
time. I may obtain this measure of force either as a continuous and permanent
record on paper passing over revolving drums, or by means of an integrating
apparatus I may indicate directly on a dial the amount of energy transmitted
in a given interval of time. I also arrange that the recording or integrating
mechanism may be started or stopped at any time without stopping the revolution
of the main pulley.
The nature of my improvements for this purpose will be readily understood on

page_text: reference to the accompanying drawings in which similar figures refer to the
same parts in all the views.
Fig. 1 is an elevation of the dynamometer..
Fig. 2 is a cross section on the line A, B, shewing the recording apparatus in
elevation.
**
-
Fig. 3 is a partial cross section on the line C, D.
Fig. 4 is a partial elevation shewing the integrating device.
Fig. 5 is another view of a portion of the integrating..device..
1 is the shaft to or from which power is being, transmitted by means of the
belt pulley 2. The pulley 2 is mounted or carried concentrically with the axis
of the shaft 1, and so long as that condition is fulfilled may be mounted or
carried in any convenient manner. In the drawings the pulley is shewn provided
with a boss 3 bored, so as to turn freely on the sleeve 4 which is rigidly fixed to
the shaft 1 and turns with it. On this sleeve 4 are attached or formed any
desired number of radial arms, or as shown in the drawing a disc may be
employed formed in one piece with the sleeve.
The driving force is transmitted from the pulley 2 to the disc 5 and thence to
the shaft 1, or vice versa, and the driving connection between the pulley 2 and
the disc 5 consists of any desired number of springs of any convenient form.
Fig. 2 and 3 show two springs 6, formed of flat strips of spring, metal bent into
the form of tongs; the ends of the springs are provided with means for attaching
them to the disc and pulley. In Fig. 1 one end 7 of each spring is shown
inserted in a slot formed in a boss 8, projecting towards the shaft 1 from the
flange of the pulley 2 the other end 9 of each spring is shown inserted in a
similar slot in a projecting piece 10 which is rigidly attached to the disc 5.
When a driving force is transmitted between the pulley 2, and the shaft 1, the
springs are distorted and one of the objects of this invention is to obtain a
continuous record of the amount of this distortion and the variations thereof over
any desired period of time. The distortion of the springs 6 is coincident with the
turning of the pulley 2 relative to the disc 5; the pulley is provided with or
carries a scribing point 11 which is in contact with a strip of paper 12 carried
on a drum or series of drums; Figs. 1 and 2 shew three drums marked 13, 14
and 15 respectively. A coiled strip of paper is wound on to the drum 13 passed
over the drum 14 and attached to the drum 15 as shown. These drums are
carried on spindles 17 which are supported in a bracket or frame 16 which is
rigidly attached to the disc 5; the drums 14 and 15 are provided respectively
with worm wheels 18 and 19 shewn in broken lines in Fig. 1. These worm
wheels engage respectively with the worms 20 and 21 which are formed on or
rigidly attached to the spindle 22. The spindle is carried in bearings formed in
the bracket or frame 16 and is provided with a worm wheel 23 meshing or gearing
with the worm 24 which is formed on the ring 25. This ring which I call the
worm ring is supported coaxially with the shaft 1 in any convenient manner, and
in the drawing is sliewn bearing on the sleeve 4 on which it can turn freely about
its axis, the collar 26 is firmly attached to the sleeve 4 and maintains the ring 25
and the pulley boss 3 in position on the sleeve. Means are provided by which the
ring may be caused to rotate relatively to the pulley 2 and the shaft 1; in the
drawing the projecting pin 27 is provided for this purpose. When the shaft 1
with the sleeve 4 and pulley 2 revolves the ring 25 would revolve therewith
unless prevented by some external means and the drums 13, 14 and 15 would
remain stationary on their axes. By connecting the pin 27 to any convenient
fixture the ring 25 is prevented from rotating with the shaft and the pulley, the
worm 24 therefore causes the wheel 23 and thereby the spindle 22 to rotate in its
bearings. This in turn causes the drums 14 and 15 to rotate on their axles
through the means of the worms 20 and 21 and the worm wheels 18 and 19
respectively. The rotation of the drum 14 draws the strip of paper from the coil on
the drum 13 and the strip is finally wound on the drum 15. The strip of paper 12
thus passes under the scribing point 11 and receives a mark or line such as is

page_text: shown at 28 on Fig. 1. The position of the mark or line relative to the edge
of the strip, or relative to a zero line already marked on the strip, is dependent
upon the amount of distortion of the springs 6 and is a record thereof. The dis-
tortion of the springs is proportional to the nett rotational-driving effort between
the shaft and the pulley, or vice versa, and therefore the position relative to the
edge of the strip of paper, or to the zero line, of any point of the line scribed on
the strip of paper by the scribing point 11 is a record of the rotational driving
effort at the instant at which the scribing point coincides with or marks that point
on the line; the same reasoning applies to all other points on the scribed line
and hence to the line in general. This combination of travelling strip of
paper 12, rollers or drums and scribing point 11 I call the recording device.
a.
When it is required to record and ascertain the amount of energy or work
that has been transmitted between the shaft and the pulley in any interval of
time the well known process of integration may be applied to the curve drawn
or scribed on the strip of paper in that interval of time or a supplementary device
as shown in Figs. 4 and 5 may be used in conjunction with the pulley 2, disc 5.
and springs 6, which have already been described. For this purpose I may dis-
pense with the drums 13, 14, and 15 and the strip of paper, in which case the
spindle 22 being rotated on its axis by the means as before described is pro-
vided at the end, remote from the worm wheel 23 with a flat smooth disc 29: In
contact with this disc is a small rolling wheel 35 which is carried by and rigidly
attached to the spindle 30; the spindles 22 and 30 are supported in brackets 31
and 32, which are firmly attached to and carried by the disc 5 but the spindle 30
may slide freely in the direction of its axis through the bracket 32; the amount
of this longitudinal motion of sliding is determined by the amount of rotation of
the pulley 2 relatively to the disc 5 as follows:-The pulley 2 is provided with
a projecting piece or finger 33 which engages with a groove 34 formed in the
spindle 30 thus the small angular motions of the pulley 2 are reproduced as longi-
tudinal or sliding motions of the spindle 30; the spindle 30 is provided with a
wheel 35 which is in contact with the face of the disc 29, the longitudinal posi-
tion of the spindle 30 and therefore of the wheel 35 is so adjusted that when the
springs 6 are in their normal condition, that is transmitting no driving force,
the wheel 35 is in contact with the centre of the disc 29, this disc 29 can there-
fore rotate without causing any rotation of the wheel 35 or spindle 30; when
however the springs are distorted the wheel 35 will take up some new positions
such as 36 or 37 Fig. 5, and in such cases will be caused to rotate by frictional
contact with the disc 29. The rotation of the wheel 35 necessitates an equivalent
rotation of the spindle 30 on its axis as they are rigidly connected. Any con-
venient revolution. counting device is employed to count and register the number
of revolutions of the spindle 30; the dial of such a device is shewn at 36.
The combination of disc 29, roller 35, sliding spindle 30 and revolution
counter 36 I call the integrating device and its mode of action is as follows:-
When the shaft 1 rotates carrying with it the disc 5 and pulley 2, and at the
same time ring 25 is prevented from rotating by being held by means of the
pin 27, then a motion of rotation on its own axis is given to the spindle 22 and
disc 29, and the amount of this rotation is proportionate to the amount of rota-
tion of the shaft 1 and the disc 5. If however the springs 6 are not distorted, or
in other words if no power is being transmitted between the pulley 2 and the
shaft 1, then the wheel 35 is in contact with the centre of the disc 29 and no
rotation is imparted to this wheel; when however the springs 6 become distorted
either by compression or by tension then the wheel 35 is carried to some such
positions as 36 and 37 respectively, and the point of contact of the wheel 35
and disc 29 is away from the centre of the disc 35 by an amount which is prac-
tically proportional to the amount of distortion of the springs 6.
The rotation of disc 29 therefore imparts a motion of rotation to the wheel 35
and thereby to the spindle 30 due and proportionate to that of shaft 1, and it
also imparts a motion of rotation to the wheel 35 and thereby to the spindle 30

page_text: due and proportionate to the distortion of the springs 6. The total amount of the
rotation of the spindle 30 as indicated on the dial 36 of the counting device is
proportioned therefore to the product of two numbers one representing the amount
of rotation due to the shaft during the time the ring 25 is held stationary and the
other representing the amount of distortion of the springs 6 and therefore the
driving effort between the pulley 2 and the shaft 1 during the same interval of
time.
The total amount of rotation of the spindle 30 as indicated on the dial 36 during
any interval of time is therefore proportioned to the amount of energy transmitted
from the shaft 1 to the pulley 2, or vice versa, in that same interval of time and
the combination of dynamometer pulley and integrating device serves as a con-
tinuous power meter.
By disconnecting the pin 27 from the part holding it stationary it is clear that
the action of the recording or integrating device will be at once stopped and that
this can be done while the dynamometer is in motion.
Having now particularly described and ascertained 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 transmission dynamometer in which the force is transmitted from a
revolving shaft to a pulley or from a pulley to a revolving shaft by means of
springs and levers connecting them, the use in combination with the said shaft
and pulley of a scribing point and a moving paper, or other medium, on which
it inscribes a line corresponding to the amount of angular movement of the pulley
with respect to the shaft at such a distance from a zero or other line on the paper
as to represent a continuous measure of the force transmitted substantially as
herein described.
2. In a transmission dynamometer in which the force is transmitted from a
revolving shaft to a pulley or from a pulley to a revolving shaft by means of
springs and levers connecting them, the use in combination with the said shaft
and pulley of an integrating mechanism actuated by the revolution of the said
shaft or pulley in such a manner as to indicate on a dial a measure of the work
transmitted substantially as herein described.
3. In a transmission dynamometer of the character described, the combination
of a disc 5 and pulley 2 with springs 6 connecting them, and the recording
mechanism consisting of the three drums 13, 14, and 15 actuated by the worms
and worm wheels 20, 21, and 24. and the scribing point 11, as herein described
with reference to Figs. 1, 2, and 3 of the drawings.
4. In a transmission dynamometer of the character described, the combination
of a disc 5 and pulley 2 with springs connecting them and the integrating appa-
ratus consisting of the counter and dial 36, the spindle 30 and rolling wheel 35
actuated by the disc 29 and the worm 24 and worm wheel 23, as herein described
with reference to Figs. 4 and 5 of the drawings.
5. The use in combination with a torsion dynamometer, of a free worm ring
working on the shaft of the dynamometer and provided with means for arresting
the rotation thereof for the purpose of imparting motion to recording or inte-
grating apparatus connected therewith, substantially as herein described.
Dat
SYDNEY E. PAGE, A.M.I.C.E..
28, New Bridge Street, London, E.C., Agent for the Applicant.