Year: 1886

page_text: I, GEORGE HERBERT POHLMANN of 40 Dawson Street, Dublin, Pianoforte Manu-
facturer do hereby declare the nature of this invention to be as follows:-
This Invention has reference to square, horizontal and upright pianos or other
stringed musical instruments; and my Improvements consist in connecting a convex
bar or bridge (made of metal or other suitable material) to the ordinary wood bridges
fixed upon the soundboard. I intend to call this metal bridge the "Counter strain
capo d'astro" and place it in a convex groove formed in the back of the ordinary wood
bridge, and made secure therein by screws or other means. The strings pass over the
wood bridge and under the convex metal bridge or bar and are thereby held down
which prevents them jumping upwards as is now the case when the piano keys are
violently struck. This metal bridge will regulate and counterbalance the down-bearing
strain upon the sound board which takes place when the strings are pulled up to pitch
consequently the tone of the piano becomes firmer and better.
The application of this Capo d'astro bridge or bar to the Soundboard helps by means
of the bearing obtained through screwing it down, to counterbalance the ordinary
downbearing strain of the strings upon the Soundboard which occurs under present
construction, relieving thereby the under strain and enabling the Soundboard by the
greater freedom it thus obtains to produce a freer, fuller, increasing, and more sustained
tone than is otherwise possible without this Counter-strain Capo d'astro bridge.
Dated thin 15th day of September 1886.
TASKER & CROSSLEY,
Halifax, Agents.

page_text: I, GEORGE HERBERT POHLMANN of 40, Dawson Street, Dublin, Pianoforte Manu-
facturer, 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 :-
This invention has reference to square, horizontal and upright pianos or other
stringed musical instruments, and my improvements consist in connecting a convex
bar or bridge (made of metal or other suitable material) to the ordinary wood bridges
fixed upon the soundboard.
I intend to call this metal bridge the "Counter-strain capo d'astro" and place it in
a concave groove formed in the back of the ordinary wood bridge, and made secure
therein by screws or other means. The strings pass over the wood bridge and under
the convex metal bridge or bar, and are thereby held down, which prevents them
jumping upwards, as is now the case when the strings are violently struck by the
"Hammers on the piano action.
"
Such being the nature and object of my invention I will now proceed to describe
the same more fully, and for that purpose make reference to the accompanying sheet
of Drawings wherein Fig. 1 is front elevation of an iron pianforte frame having my
improvements applied thereto, Fig. 2 is section of same taken through the line a-b.
A is the bracing forming the back of the pianoforte, 'B the wrest plank, C the sound-
board and D the soundboard bar which is made fast at each end to the parts marked c
and'd and e is a metal bridge under which the steel strings pass on their way to the
pins g attached' to the iron frame'E.
"My improvements are shown at F and G which represent metal bars or bridges
called by me the "Counter-strain саро d'astro."
'These metal "bars or bridges are placed into grooves formed in the back of the
ordinary wood bridges' and j. It will be observed in the Drawings (see Fig. 3 which
is an enlarged section of the "Counter-strain Capo d'astro" F and wood bridge h) that
the string g' passes over the wood bridge h and under the metal bar F, the said bar
being kept in position' by screws k or other suitable means.
Fig. 4 is a diagram "shewing more clearly the position and direction of othe
strings f.
The application of this Capo d'astro Bridge or bar to the soundboard' helps (by
means of the bearing obtained through screwing it down) to counter-balance the
ordinary down bearing strain of the strings upon the soundboard which occurs under
present construction, relieving thereby the undue strain and enabling the soundboard-
by the greater freedom it thus obtains to produce a freer, fuller, increased, and more
sustained tone than is otherwise obtainable without this Counter-strain Capo d'astro
bridge.

page_text: The application of these metal bars or bridges to pianofortes also overcomes another
defect-namely the destruction of the concaved form of the soundboard through the
undue down-bearing pressure of the strings upon it; which takes place on the strings
being pulled or drawn up to pitch, and which, though oft recurring, cannot be remedied
in the present construction of pianos. This defect is overcome by the manipulation of
the Counter-strain Capo d'astro bridge which permits of the soundboard being regulated
to its proper concave form or shape.
Also by the use of this new bridge, the soundboard can be freed in many ways, such
for instance, as allowing lighter bars to be fixed to it, whereby greater freedom is
obtained, consequently producing an increased tone.
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 :-
Firstly. The method of relieving the down bearing strain on the soundboard of all
classes of Pianofortes or other stringed musical instruments by means of a bar or bridge
built substantially as described, and shewn in the various figures.
Secondly. The employment of a regulating bar or bridge for allowing the down
bearing strain to be removed or regulated by altering the level of the strings.
Dated th: 15th dox of Iuno 1887