An Improved Rotary Speed Indicator.
Year: 1892

page_text: Date of Application, 9th Jan., 1892-Accepted, 13th Feb., 1892
COMPLETE SPECIFICATION.
An Improved Rotary Speed Indicator.
I, ERNST HEINRICH ARI, of Laboe in the Empire of Germany, 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 consists in a speed indicator for measuring the rotary velocity of
shafts or other rotary elements of machines and its improved construction is based
on the principle of employing the so-called centrifugal force of a weight acting on
a lever pivoted on a rotary disk to be brought into connection with the machine the
speed of which is to be measured, so that the said weight acts on a piston in a
cylinder filled with liquid and causes the liquid to operate a prèssure gauge by
which the speed is thus indicated.
The space for liquid in the cylinder communicates through the hollow shaft of
the disk with a hollow space in one of the bearings of the shaft so that the pressure
of liquid in the cylinder and in this space is at all times the same on both and can
be read on the gauge in communication with the space in the bearing.
The improved speed indicator is illustrated in the annexed drawing in Fig. 1 in
elevation and in Fig. 2 in plan, both figures being partly in section..
The disk S on the shaft W is carried in bearings on the frame G and is driven
by belt pulley and bevelled wheels eel or by equivalent gear from the shaft
machine or engine the speed of which is to be indicated. A is the cylindrical
vessel on the disk S in which the liquid is pressed by the piston or plunger & the
rod or pitman k' of which is connected to the arm a of the lever H which carries
on its other arm the weight P and is pivoted on the disk S at c.
When the disk S revolves the lever H swings outward and the piston k is driven
into the cylinder A driving some of the liquid out of this cylinder through the
pipe m into the shaft W, liquid thus issuing from the lower end of the shaft at i in
the spaces in one of the bearings and passing in the pipe g to any suitable pressure
gauge until the centrifugal force of the weight P is balanced by the resistance in
the gauge and the pressure indicated thereon is equivalent to the speed of rotation.
In place of a single weight P, it is preferable to have two weights P and Plat
opposite ends of a diameter of the disk S. The second weight PP on a lever H¹ is
connected by a forked connecting bar z and cross head a' with the rod and acts
on the rod in the same direction as the weight P.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is ;-
An indicator for rotary speed having a pressure cylinder on a rotary disk or body,
and a piston in said cylinder in connection with a centrifugal weight or weights
whereby liquid in the said cylinder may be pressed therefrom towards the centre of
the disk and there communicate through a hollow central shaft of the disk or
otherwise with a stationary pressure gauge for the purpose set forth.
Dated this 9th day of January 1892.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.