Year: 1895

page_text: Date of Application, 16th Jan., 1895-Accepted, 2nd Mar., 1895
I, FERDINAND PIETSCHMANN, of No. 25, Brunnenstrasse, Berlin, in the Empire
of Germany, Manufacturer, 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 relates to an improved whistle, capable of producing a variety of
sounds, from the deepest up to the highest note of the scale, howling or producing
at will a shrill, piercing sound.
In the accompanying drawings,
Figure 1 is a central, longitudinal section of the whistle ;
Figure 2 is a cross-section of the same, showing in plan the lower one of the two
perforated discs arranged one over another;
Figure 3 is a side view of the said lower disc, secured within the pipe of the
whistle;
Figure 4 is a plan of the top or cover of the whistle ;
Figure 5 is a side view of the upper disc arranged to turn freely within the pipe
or casing of the whistle, and Figure 6 is a plan of the said loose disc.
The whistle of my invention consists of a pipe or casing A, of any convenient
material and shape; the mouth-piece of the whistle may be integral with the pipe A,
or screwed or otherwise secured to the same. Within the upper, preferably
cylindrical part of the pipe or casing A, a disc B, is secured having a suitable
number of perforations 6, traversing the disc in an oblique position, as clearly
shown in Figures 1, 2 and 3. The upper surface of the said disc B has a step-
bearing, preferably formed in the end of a steel-screw 61 centrally traversing the
said disc B. The upper or forward end of the whistle-pipe A, is closed by a
cover C, having sufficient apertures c, to allow the blast to pass out. In the centre
of said cover C, a step-bearing c¹ is provided opposite the step-bearing b¹ of the
disc B. The said bearing c is preferably provided equally in the end of a screw-
plug, traversing the cover C. Between the said cover C and disc B, a disc D, is
loosely fitted into the cylindrical portion of the whistle-pipe or casing, A. The
said disc D has perforations d, taking an inclined position in the opposite direction
of those of the disc B, as shown in Figure 1. The said disc D, has a central
pin d', projecting on both sides and the pointed ends of said pin are fitting the
step-bearings and c¹ of the disc B, and cover C respectively. The cover C is
screwed on to the pipe or casing or otherwise adjustably secured upon the same
and it will be easily seen, that on screwing the said cover more tightly down, the
pin d', of the disc will have more frictional contact with the step-bearing c¹, than
if the said cover (is being partially unscrewed. Thus, by adjusting the position
of the cover C, the disc D, will be allowed to turn more or less freely in its step-
bearings & and c¹.
The sounds are produced by blowing into the mouth-piece of the whistle. The
blast, traversing the perforations of both discs B and D, owing to the oppositely
oblique position of the said perforations, forces the disc D, to revolve, and the
speed of the revolving motion will be proportionate, first, to the power of the blast
and, secondly, to the frictional resistance encountered by the journals of the disc D,
within the step-bearings and c¹. It will be easily understood, that, as the
disc D, is but slowly revolving, the passage of the blast through the perforations
of the two discs B and D, registering with each other at short intervals as they
n

page_text: pass each other, will havè a larger area, as if the disc D, is turning at a higher
speed, and that, accordingly, a lower speed of the disc D. will produce deeper
sounds, than a higher speed. By blowing softly, then, deep sounds of the whistle
are produced, and by blowing hard, shrill and piercing sounds will come forth.
But the notes of the scale do not entirely depend on the power of the blast applied,
but also on the frictional resistance in the bearings 6' and c', adjustable by means
of the variable position of the cover C. Thus, by tightly screwing the cover on,
a strong blast will not be able to produce as shrill sounds, as a soft blast with a
loosely fitting cover.
0
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. A whistle, having within its pipe or casing two discs, the perforations of one
or both of which have an oblique position and one of which discs is arranged to be
turned by the blast, substantially as and for the purpose set forth.
2. A whistle, having within its pipe or casing two discs, the perforations of one,
or both of which have an oblique position, one of which discs is arranged to be
turned between step-bearings, one of which is made adjustable, substantially as and
for the purpose, set forth.
3. A whistle, having within its pipe or casing two perforated discs, one of which
is arranged to turn with its central piu in step-bearings provided respectively in
the fixed disc and the adjustable cover, substantially as described.
Dated this 15th day of January 1895.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.