IMPROVEMENTS IN SPEED INDICATORS AND APPLIANCES CONNECTED THEREWITH
Year: 1884

page_text: therewith.
I HEINRICH WILHELM SCHLOTFELDT Engineer of Kiel in the kingdom of
Prussia do hereby declare the nature of my said invention for "IMPROVEMENTS
IN SPEED INDICATORS AND APPLIANCES CONNECTED THEREWITH to be as
follows:-
This invention relates to speed-indicators and has for its object to indicate or to
register the variations of speed of vessels and revolutions of engines, shafts and
other mechanical elements by means of a mechanism such as an air or fluid pump,
a fan or other implement moved by the respective motor or shaft and constructed
in such a manner, that atmospheric air or other other fluid is more or less com-
pressed. The compressed air is by a tube or tubes communicated to a manometer
or other indicating or registering apparatus of suitable construction.
If the air pressure is regulated by an intermediate regulator or valve arrange-
ment proportional to the variations of speed of the respective engine, shaft or the
like, the movements of the indicating hand or registering pencil or pointer can be
made proportional to the variations of speed and a scale of constant divisions can
be applied to the manometer or registering apparatus. The indicator may be made
self registering by the compressed air acting upon the surface of a liquid contained
in a metal case that communicates with a cylinder and piston in such manner that
the piston is raised and lowered according to the rise and fall of pressure,
The motions of the piston are by means of a rod or lever transmitted to a pencil
or pointer registering its movements on the surface of a revolving drum driven by
clockwork.
Instead of compressure rarefaction of air may be employed as a means for
transmitting the speed variations. This may be executed by a vacuum pump, an
exhauster or by centrifugal action.
In case centrifugal power is employed for compressure of the air, the respective
motor or shaft is put in gear with a fan, revolving in a case containing liquid. By
the action of the fan the liquid is thrown against the circumference of the case
and exits through a pipe or pipes into a vessel or cylinder in which either direct,
or by means of a piston or a float, air is compressed. The greater the velocity of
the fan, the greater is the compression of air and these variations of pressure can
be transmitted to the indicating manometer or registering apparatus as before
described.

page_text: •
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Improvements in Speed Indicators and Appliances Connected
therewith:
I HEINRICH WILHELM SCHLOTFELDT, Engineer of Kiel in the Kingdom of
Prussia do hereby declare the nature of my invention for "IMPROVEMENTS IN
SPEED INDICATORS AND APPLIANCES CONNECTED THEREWITH" and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This invention has for its object improvements in the means of indicating the
variations of speed of mechanical elements, or of vessels or other moved vehicles.
The transmission of motion to the manometer or indicator is effected either by
compression or by rarefaction of air, regulated by a valve or other suitable element,
enclosed in the air-tubes and influenced by a mechanism driven or moved by the
machine or element, the movement or revolution whereof has to be measured.
The regulation of the air pressure may be effected by a centrifugal regulator, or
by pressure or suction executed on a liquid. Some of the arrangements applied by
the inventor are shown in the accompanying sheet of drawings.
Fig. 1 designates a centrifugal pump with radial blades F. A is the casing in
which the blades, mounted on a hollow shaft W rotate. The hollow part of W is
by means of radial openings in communication with the casing enclosing blades F
and by borings in the circumference of the casing is again in communication with A.
A centrifugal pump of construction as before described may be used for transmitting
the air pressure to the apparatus shown in Fig. 2 in which A designates a cylinder
with two pistons k and k¹ connected to each other by a stay. The openings a and b
are by means of pipes connected to the corresponding openings a¹ and b¹ of the
centrifugal pump, and the pump is rotated by the shaft or element the velocity of
which has to be measured. The liquid by which cylinder A. has partly been
filled is by the action of the pump removed through opening a from above the
piston and through b forced into cylinder A underneath piston k in consequence
of which both pistons rise. If tube r¹ communicates with the open air and r with
a manometer, the hand of the latter will rise by the compression of air.
'
If the communications between cylinder and pump be exchanged, thus, that a is
connected to b¹ and b to a' the pistons would descend and the pressure of air above
piston be reduced.
If the above described apparatus is used for registering the velocity of a vessel,
opening b will be caused to communicate with the water outside the vessel by
means of a tube ending at right angles against the flow of water, whilst opening a
'communicates with the water by a tube the mouth of which is directed at an angle
of about 41 degrees against the direction of motion.
In the construction according to Fig. 3 the air pressure produced by the velocity
to be measured is transmitted to piston k¹ by a piston rod to which valve vis
attached, the latter closing more or less an opening 3 of the cylinder cover.
Through tube the air compressed by a ventilator enters cylinder A and acts
against piston k¹. Tube r communicates with the manometer. If the velocity

page_text: accelerates, the pistons rise and close valve v in consequence of which the air.
pressure against piston k¹ is enlarged and indicated through tuber by the mano-
meter. If the velocity is retarded piston k¹ descends through the air pressure from
tube and opens valve v.
Fig. 4 is a modification showing a similar arrangement as Fig. 3, but constructed
for rarefaction of air in tube r¹
In Fig. 5 instead of the rod a mantel is used for connecting the two pistons
which appears in this case as a hollow swimmer B. Tube 1 terminates in the
hollow part of swimmer B, otherwise the action is analogous to that of Fig. 2.
Fig. 6 shows a similar arrangement as Fig. 5 but instead of the solid tubes of
swimmer B india-rubber hose or other flexible pipes are used.
In Fig. 7 tube that communicates through with the compressed air of a fan
or ventilator and through r with the manometer, terminates in cylinder A, at the
level of liquid attained while the machine or shaft etc is at a standstill. In this
case an air pressure cannot arise in the pipe system as the air can exit at the open
end of tube . If k and k¹ rise in manner before described, the liquid above
piston k' also rises and closes the mouth of tube and the air cannot escape before
the air pressure in is sufficient to overcome the weight or pressure of the column
of liquid closing the end or mouth of tube 7ª. If the liquid rises proportionally
to the velocity (by a centrifugal pump) the pressure also rises in the same
proportion.
In the apparatus represented in Fig. 8, the compressed air from tube ¹ enters
underneath of valve vand above piston k. Tuber leads to the manometer. By
the velocity to be measured a proportional air-pressure is produced in cylinder A
and by means of piston k and rack is transported to spur wheel h, which moves.
by disc n the piston k, of another cylinder and by disc n¹ a weight P, that influences
valve v. In the position shown in the drawing the apparatus is at rest and valve v
not loaded, in consequence of which the air can freely escape. If weight P is by
disc n¹ shifted towards valve v, and this latter be loaded correspondingly, the air
pressure rises in the tube-system as well as against piston k; or on the other hand
if by disc n the piston k is moved forward the air pressure rises proportionally to
the resistance of the piston, whilst the lever arm of the disc changes in same
proportion. The resistance against the regulator consequently changes according
to the square of the air-pressure.
lever a.
In the modification shown in Fig. 9 the air pressure produced by the velocity or
revolution to be measured and transported by a double armed lever acts at point C,
against lever a, that fulcrums at a point e. The air pressure in box or casing lis
by means of a diaphragm d, an Evans lever x, and roller or disc c transported to
If the air pressure rises in l, it rises at same time in a vessel y partly
filled with water and connected to l, by tube r¹; a swimmer u ascends and descends
with the rise and fall of pressure and this swimmer moves by means of a con-
necting rod, diac n in upward and down direction. The connection between rod
and disc allows of a sliding side-motion of said disc n, and as the movements of
diaphragm d, are in such manner transported on to the lever arm that its length
increases proportionally to the increase of air pressure, the pressure at O must
increase according to the square of air pressure. Tube communicates with the
air-pump and with the manometer; v designates a valve, regulated by the
air-pressure. If the velocity accelerates or the number of revolutions increase,
diaphragm d is by the counter pressure exerted at C forced back and valve v, is
closed by connecting rod i. The air pressure rises in until it counterbalances
the pressure at C. On the other hand if the velocity decreases or the revolutions
reduce in number, valve opens and air escapes up to the moment where
equilibrium takes place.
Instead of a swimmer u, a piston or any other suitable arrangement may be
used for producing a movement that is proportional to the air pressure.
Fig. 10 is a modification in which rarefaction of air is used instead of air-pressure.
The pressure of air produced by the velocity to be measured acts at C, on a

page_text: double armed bent lever a that fulcrums at c. If the air pressure is reduced
in the tube system as well as in y, swimmer u decends and draws lever b
turnable at a downward in proportion to the degree of rarefaction. A weight P
turnable on bolt i acts on lever b. The more swimmer u descends, the more is
fulcrum c¹ moved downward in consequence of which the arm of lever b on
which weight P acts is proportionally prolonged. In the same proportion the
arm of lever a onto which the weight of P is transported by lever b is also
prolonged.
The action of the apparatus is otherwise analogous to that before described.
To indicate at same time, whether the engine goes forward or backward, a
driver M (Fig. 11) may be connected to the rotating shaft. Lever d that fulcrums
at e, moves a slide valve formed of the pistons 8 and 81 Lever d is by a spring
pressed slightly against driver M. In the position of lever d shown in the drawing a
is by means of tube c in communication with the swimmer and 6 by b¹ with
cylinder A. If the machine is reversed lever d, will be turned by the driver M and
the valve moved to the right so that a, communicates by a¹ with cylinder A and
b by c with the swimmer. By these alterations of position the air pressure in the
manometer is either enlarged or reduced.
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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
A speed indicator in which an air pressure produced by the engine, ship or
machine element, the velocity of which has to be measured, acts against a valve or
other suitable device, enclosed in the air-tube, system and influenced in its move-
ments by the enclosed air in such manner, that the pressure of the enclosed air is
regulated in a certain proportion to the speed as herein set forth and shown by the
drawings.