Year: 1887

page_text: I, WILLIAM PARKINSON of Accrington in the County of Lancaster, Commercial
Traveller, do hereby declare the nature of this invention to be as follows:-
This Invention has for its object to provide an easy means of ascertaining the power
required to drive machines possessing a rotary movement and to register the same by
means of marks drawn by a pencil, or other instrument upon a surface provided for
the purpose According to this invention I employ a wheel with flexible arms, each
arm consisting of two or more flat springs which are interchangeable. Their number
may be varied by additions or removals to suit various powers.
These springs are held rigidly in suitable jaws upon the boss of the wheel and their
outer ends are held loosely by the rim of the wheel.
The rim has a rotary movement upon the boss limited by stops in either direction
which prevent the springs from being overstrained.
On the boss of the wheel is a radial arm to which a pencil or stylus is affixed. This
arm travels by means of a differential motion along the boss, but its angular
movement corresponds exactly with that of the boss of the wheel.
The driving power being made to pass through the rim of the wheel to which a
card is attached by means of a suitable card holder.
The pencil or stylus draws a diagram across the card which measures all the
angular differences of position between the boss and the rim during the period of the
experiment.
The power in foot pounds absorbed by the machine is ascertained after it is stopped
by 'hanging a weight on the periphery of the wheel untill the pencil reaches the mean
height of the diagram curves and then multiplying the weight into the speed in feet
per minute of the periphery.
In this manner variable resistances which may occur during the running of a
machine or at starting may be observed and estimated.
D 10th of Ontahan 1087
PETER MCGREGOR,
5, John Dalton Street, Manchester,
Agent for Applicant.

page_text: Improvements in Dynamometers.
1, WILLIAM PARKINSON of Accrington in the County of Lancaster, Commercial
Traveller, 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 :—
My invention has for its object to provide an easy means of ascertaining the power
required to drive machinery possessing a rotary movement and to register the same
by means of marks drawn by a pencil or other instrument upon a surface provided for
the purpose, in combination with a wheel having flexible arms, each arm consisting
of two or more flat springs which are interchangeable and their numbers may be
varied by additions or removals to suit various powers.
In the accompanying sheet of drawings (which are drawn half size) the same letters
refer to similar parts as shewn in the different figures.
Figure 1, is a section, through the perpendicular dotted line X shewn in fig. 2.
Figure 2, is a front view of the wheel, as shewn beyond the dotted perpendicular
line shewn in fig. 1.
a is the boss of the wheel forming the dynamometer, 6 the flexible arms, composed
of a variable number of spring blades and through which the power to be measured is
passed, the boss a has projecting clips c to which the spring blades are ridgidly
attached by set screws as shewn in the drawings or otherwise—the other ends of
the springs are held loosely between jaws d, projecting from the side of the circular
plate or rim e which rim is fitted on to a shoulder of the boss a and works loose
thereon, the plate or rim e is held in its position on the boss a by a collar or flange f
fixed to the boss a by set screws g as shewn in the drawings-or in any other suitable
manner the collar or flange has two projections or stops / which works in a space i
cut out of the plate or rim e, the plate being free to move on the boss a either way
within the limit of the projections or stops of the flange or collar f, which stops are
to prevent the springs being strained-the exact shape of the collar or flange fis
shewn in fig. 2, in dotted lines.
On a prolongation of the boss a there is mounted a collar j, with a screw cut upon
it this screwed collar is made to revolve by means of a grooved band pulley k
attached to, or forming part of the screwed collar-a nut 7 working or running on
the thread of the collar carries a pencil arm m. having a knuckle joint, the pencil n
works freely in a hole in the arm and is kept up against the card by a small spiral
spring, the pencil arm m is kept in its position by two fingers o o fixed to and pro-
jecting from the stop h of the flange or collar which pencil when the apparatus
work draws the diagram lines on the card p which is held in a card holder q attached
by screws or any convenient manner-to the plate or rim e.
'at
The dynamometer is attached to the machine to be tested by keying or otherwise
fastening the boss a to the driving shaft, near to the fast pulley, which is unkeyed or
made loose, the pulley is then connected by studs, or in any other convenient

page_text: manner, to the plate or rime of the dynamometer, the power is thus taken through
the flexible arms b to the boss a and drives the machine.
The springs of the arms must be strong enough to drive the machine without the
projections or stops h of the fixed collar or flange f coming in contact through the
openings with the rim e-The diagram is then taken in the following manner,
starting with the pencil in the position shewn in fig. 1.
The hand wheel or double grooved band pulley shewn at Fig. 3-is geared by
means of two light cotton cords with the pulley k of the screw collar j and the pulley's
which is made fast on the end of the boss a-These cords may be of any equal suitable
length, motion is transmitted from the fixed pulley s on the boss a to the pulley k of
the screw through the band pulley r fig. 3-the grooves of the pulley are of unequal
diameters, the one being say 34" and the other 4", consequently the relative speeds of
the pulleys sand & will be as 31 to 32-the nut 7 which carries the pencil arm m will
travel towards the wheel at the rate of one thread of the nut for 31 revolutions of the
dynamometer and a continuous diagram will be produced on the card, the length of
the screw (or about two inches) illustrating every variety of strain to which the
springs has been subjected during the period of test-If a second diagram is
required it will suffice to change the cords, and turn the hand wheel so that the small
groove of the pulley shall be opposite the pulley k of the screw and the large groove
opposite the pulleys, the pencil will then travel back to the position as shewn in
Fig. 1.
The instrument is both right and left hand, and if made with a hole 21" diameter in
the boss a-it may be bushed to fit any smaller size of shaft, and may be fixed on the
middle or end of a shaft, and if the hand wheel cords are made long enough, the
operator may stand on the ground while making a diagram on an overhead shaft.
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
The means used as described and set forth in the drawings of causing the pencil
to travel accross the card, in combination with the flexible arms of the wheel.
13
1000
PETER MCGREGOR,
5, John Dalton Street, Manchester,
Agent for Applicant.