Apparatus for Use with Kettledrums for Automatically Tightening Up or Slackening the Skin to Maintain same at any Desired Tension.
Year: 1895

page_text: Date of Application, 2nd Mar., 1895-Accepted, 4th May, 1895
COMPLETE SIECIFICATION;
Apparatus for Use with Kettledrums for Automatically Tightening
Up or Slackening the Skin to Maintain same at any Desired
Tension.
We EMANUEL REIOHER and FRANZ MORITZ FRIEDBERG of Neider-
Schonhausen near Berlin, in the Empire of Germany, Inventors, 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:-
The present invention relates to an apparatus designed to maintain the skin of a
kettle-drum automatically at a uniformn tension, (when the said skin has been once
correctly tightened up to the proper pitch) that is to say, to keep the skin at the same
tone or pitch, so that the instrument will not be affected by the state of the
atmosphere, and the skin, which rapidly absorbs moisture from the atmosphere
and becomes thereby altered in tension and in tone or pitch, will always be
automatically tightened up, or slackened according as the skin is rendered slack
or rendered tighter by absorption of moisture or on becoming dry as the case
may be.
The accompanying drawing illustrates in vertical section a kettle-drum provided
with the new apparatus.
The drum a, is supported in the well-known manner on three legs bb, which.
carry the drum by means of the ring e, and are prevented from spreading. apart
by stays or struts c'. The skin d, is also fixed to the drum in the usual manner,.
namely, by being mounted on a ring e, and drawn over the beaded edge a¹ of the
drum.
The forcing down of the ring e, and therefore the tightening of the skin of the
drum-head, is effected by means of a ring f, from an annular piece h, which is
arranged underneath the drum, and concentrically with the latter. The annular
piece h, is connected with the ring f,.by means of connecting rods 9. These rods 9,
are attached at the upper ends to the ring f, by means of binge-like lugs f', and at
their lower ends to the annular piece by means of hinge-like lugs h. In the hub /*
of the annular piece h there is guided a tightening bolt or screw i, the lower part
of which projects through the guide or eye-piece rigidly fixed to and carried by
the stays caud this bolt i is connected to a lever which is pivoted in a clip
carried by one of the stays cl.
This lever k is connected by means of a connecting rod / to a lever m which is
pivoted to a leg b by means of the clip m'. The free and longer end of the lever m
is serrated or formed with notches, or otherwise suitably formed to carry thoreon
a readily movable loop ", which rests in the notches and serves to carry a
weight o
It will be readily understood from the drawing that the conuecting rod / is drawn
up by the weight o, with the result that the tighteuing screw i, and with it, the
annular piece h, the rings f and e, are pulled down, and thereby the skin is
tightened. The wing-nut (or equivalent) on the tightening screw i has for object
to give any desired position to the lover m.
The mode of operation of this apparatus is extremely simple.
The more the weight o is moved nearer to the end of the lever m, the greater
will be its leverage in consequence and the drum-head will be stretched with so
maah had fauna
'

page_text: After the loop n has been placed in a determined position and thus a desired tone
or pitch has been produced, this tone or pitch will remain uniform, because as soon
as the drum-head absorbs moisture or has a tendency to become slack from any
cause, it will be drawn by the uniform leverage of the weight, to such an extent
over the edge a¹ that it will always keep the desired tension and the desired pitch
or tone. If the drum, set to the proper pitch, and which has absorbed moisture in
its drum-head, be placed in a warm, dry room, the drum-head will very quickly
yield up its moisture and become tighter. Now, as the levers do not meet
any obstacle, the improved tension apparatus is able to readily follow up the
contraction of the skin or drum-head, so that the drying of the skin does not
cause any alteration of the tension, and therefore no change of tone or pitch is
produced.
A great advantage of this improved tension apparatus consists in that the drum
can be brought to the proper pitch with the greatest ease, by merely shifting the
loop with the weight o.
The notched end of the lever m may be provided with a suitable scale or index
thereon for the purpose of enabling the weight o, to be shifted quickly and
correctly for any determined pitch or tone.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. An apparatus for use with kettle-drums, for automatically tightening up or
slackening the skin or drum-head d, consisting of the arrangement and combination
of a pivoted lever such as m, with a weight o, (capable of horizontal adjustment
according to the desired pitch or tone) which latter holds down a ring such as ffor
tightening the drum-head d, in such a manner, that the tension of the latter will
remain uniform in varying conditions of moisture or dryness substantially in the
manner and for the purposes hereinbefore described.
2. The apparatus for automatically tightening or slackening kettle drum-heads
arranged, combined, and acting substantially in the manner and for the purposes
hereinbefore described and illustrated in the drawings hereunto annexed.
Dated 2nd day of March 1895.
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.