AN IMPROVEMENT IN PIANO-FORTES
Year: 1883

page_text: LETTERS PATENT to Carl Camin, pianoforte maker of Berlin doing business
under the firm of CA W Camin of Berlin N Prussia German Empire for an
Invention of "AN IMPROVEMENT IN PIANO-FORTES ”
PROVISIONAL SPECIFICATION left by the said Carl Camin at the Office
of the Commissioners of Patents on the 16th February 1883.
CARL CAMIN pianoforte maker of Berlin doing business under the firm of
C, A, W, Camin of Berlin N Prussia German Empire "AN IMPROVEMENT IN
PIANOFORTES 33
"
This invention has for its object to obviate in pianofortes what is known as
"knocking" which arises from the impact of the hammers upon the strings
becoming audible prior to the sound of the string itself and which occurs more or
less in the treble of all pianofortes. This object is effected by the employment of
my new treble bridge." Hitherto this bridge has been formed by a curved solid
ledge or strip glued upon the soundboard, Now according to this invention the
treble bridge is constructed and arranged so that a channel may be formed between
the sounding board and bridge and open at both ends such channel gradually
widening towards the shortest string. The following is an example of my said
invention The "treble bridge" consists of a flat central piece having glued on
it's upper side a curved strip. On the other or under side are two strips one of
which is also about the same length but cut so as to be narrower in one place. On
the same side of the central piece is also glued a shorter piece which is placed
opposite to the cut part of the former piece thus forming a channel when the bridge
is glued to the sound board. The strings bear upon the strips and by means
thereof as well as of the whole bridge (when constructed as described) communicate
their vibration to the sound board. Upon the hammer striking the string the air
in the channel (formed as described between the bridge and the sound board) is
caused to vibrate and the sonorous vibrations are at once transmitted towards
both sides of the bridge, thus the production of sound coincides with the impact of
the hammers upon the strings the small quantity of air enclosed in the channel
between the soundboard and the bridge being more quickly influenced by the
vibration of the string than the large unlimited mass of air which is only caused
to vibrate by the sound board,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Carl Camin in the Great Seal Patent Office on the 16th August
1883.
CARL CAMIN pianoforte maker of Berlin doing business under the firm of
CA W Camin of Berlin N Prussia German Empire "AN IMPROVEMENT IN
PIANO-FORTES
" .
This invention has for its object to obviate in pianofortes what is known as
"knocking" which arises from the impact of the hammers upon the strings
becoming audible prior to the sound of the string itself and which occurs more or
less in the treble of all piano-fortes. This object is effected by the employment of
my "new treble bridge." Hitherto this bridge has been formed by a curved solid
ledge or strip glued upon the soundboard. Now according to this Invention the
treble bridge is constructed and arranged so that a channel may be formed between
the sounding board and bridge and open at both ends such channel gradually
widening towards the shortest string, The following is an example of my said
Invention The "treble bridge" consists of a flat central piece having glued on
its upper side a curved strip. On the other or under side are two strips one of
which is also about the same length but cut so as to be narrower in one place. On
the same side of the central piece is also glued a shorter piece which is placed
opposite to the cut part of the former piece thus forming a channel when the bridge
is glued to the sound board. The strings bear upon the upper strip and by means
thereof as well as of the whole bridge (when constructed as described) communicate
their vibration to the sound board. Upon the hammer striking the string the air
in the channel (formed as described between the bridge and the sound board) is
caused to vibrate and the sonorous vibrations are at once transmitted towards
both sides of the bridge thus the production coincides with the impact of the
hammers upon the strings the small quantity of air enclosed in the channel
between the soundboard and the bridge being more quickly influenced by the
vibration of the string than the large unlimited mass of air which is only caused
to vibrate by the soundboard.
And in order to explain my said Invention more fully I will now proceed to
describe the same with reference to the accompanying sheet of drawing.

page_text: enclosed between the soundboard and the bridge in the channel f is more quickly
influenced by the vibration of the strings than the large unlimited mass of air
which is only caused to vibrate by the soundboard. The ledge or strip d is
bevelled off at g to afford a larger effective surface between the ledges and at the
same time to afford a sufficient surface for glueing the edges d'and e to the
soundboard
Having thus described and ascertained the nature and object of my said invention
and the means whereby the same may be carried into practical effect I would
remark in conclusion that what I claim as my invention and desire to secure by
Letters patent is :-
A Treble Bridge for piano-fortes generally consisting of the combination of the
bridge with the strip c carrying the strings also the lower ledges or strips d and e
so as to form a channel in connection with the soundboard all substantially as and
for the purposes set forth.
In Witness whereof I the said Carl Camin have hereunto set my hand and
seal this first day of August in the year of our Lord one thousand eight
hundred and eighty three
CARL CAMIN. (L.S.)