IMPROVEMENTS IN SPEED INDICATORS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, FERDINAND REINHARD JOHN Mechanician in Kiel (Germany) do hereby
declare the nature of my said invention for IMPROVEMENTS IN SPEED INDICATORS
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Through the driving apparatus (a small ventilator constructed specially for this
purpose), which is connected with the motor to be observed by means of a strap-
disc and which produces the same effect both in the forward and the backward
motion, an air-pressure is exercised by means of a tube-conduit d, which is screwed
on to support c, on the surface of the fluid contained in the vessel e of the indicating
apparatus B. Inside of the vessel e is the tube ƒ communicating with it, and in
this tube is a float g. According as the air-pressure in the outer tube e is greater
or less the float will rise or fall and will indicate its position, by means of the cog-
bar h and of the cog-wheel i fastened to the indicator-shaft, on the alabaster-glass
plate k, which is provided with a scale. Then as a certain height of the water-
column corresponds with a certain number of revolutions of the wing-wheel
belonging to the driving apparatus, you are able by means of this apparatus to
read off exactly the number of revolutions of a machine without further help. The
fluid contained in the indicating apparatus consists of water and glycerine and is
introduced through a fill-hole situated on top. By means of screw the level of
the fluid can be regulated through the piston m.
In order to throw when it is dark sufficient light on the scale, a candle-holder n
(or else a lamp) is placed inside the frame and behind the light is a reflector.
The same effect of the indicating apparatus can be attained in an analogous way,
which is by connecting the air-tube with the suction opening of the ventilator,
which produces a vacuum in the vessel e in the place of air-pressure.
In order to ascertain if necessary in the case of ships etc. in which direction
(forwards or backwards) the engine is working, there is on the driving apparatus A
a set of screws with a lever-flap, which latter, when the engine moves forwards,
closes the air-tube q the mouth of which is there, and leaves it open when the
engine is reversed; through this and by means of the air-tube conduit pressure is
exercised on the fluid in the vessel r and consequently the float t contained in the
communicating tube 8 begins to rise. The float bears a shield with the inscription
"backwards" which however is covered by a plate u when the engine is going
ahead.

page_text: Or else there is in the driving apparatus a set of screws with a springing metal
plate v, which in consequence of the current of wind presses by means of the hard-
rubber plate w and corresponding with the motional direction either against the
contact-screw or is held distant from it. In the first case it effects a closing of the
electric conduit, which joins this spring with the magnet-rollers of the indicating
apparatus B and with the elements, by which means the pointer y is drawn towards
the other side.
The advantages of this apparatus over other constructions are as follows:
1.) With one driving apparatus any number of indicating apparatuses can be
connected at any distance whatever.
2.) All expensive transmission shafts and wheel-beams are done away with;
on the other hand a thin tube-conduit can be applied every where without much
expense and with little trouble.
3.) The functioning of the apparatus is quite independent of temperature and
barometric influence.
4.) The simultaneous and reliable indication of the motional direction.
5.) The illumination of the apparatus.
6.) The decrease of all complicated mechanisms which ensures a reliable func-
tioning of the apparatus.
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, by means of a ventilator operating similarly in
both motional directions, a rising or falling of the fluid-columns corresponding
with the rates of speed takes place in two communicating tubes of which the one
is connected with the ventilator and the other provided with a float which sets
the pointer in motion, whereby at the same time according to the motional
direction this motional direction is indicated by means of a second air-tube conduit
and through a second float, or else a springing metal plate is brought in conse-
quence of the current of wind either in connection or out of connection with the
contact-place of an electric apparatus, which indicates the motional direction.
Dated this 8th day of December 1884.