IMPROVEMENTS IN PIANOFORTES
Year: 1885

page_text: We FRANK COLLINS and HARRY COLLINS, both of 43 James Grove, Peckham
in the County of Surrey, Gentlemen, and GEORGE WHEELER 9 Cloudesley Square,
Islington in the County of Middlesex, Gentleman do hereby declare the nature of
our invention for IMPROVEMENTS IN PIANOFORTES to be as follows:-
The object of this invention is to remove the tendency which the strings of
pianofortes have, to drop out of tune, which tendency is due to the "give" of the
Wrest pins under the strain of their respective strings.
In attaining this object, we utilise the plank bridge over which the wires are
strained, not only as a support for the wires, but as a holdfast in conjunction with
overlying gripping plates.
.
Supposing the plank bridge to be made of cast iron (as is usual), we level it in
the usual manner, then, by means of a file or otherwise, roughen the surface to
prepare it to receive the strings.
To this bridge we apply a series of gripping plates some six inches in length,
more or less, which extend across the instrument, and serve to cover all the
stringa-These plates we secure to the bridge by screws, or nuts and bolts, taking
care that each plate shall bear evenly on the strings which it overlies, and hold
them firmly at tension.-The tuning of the instrument is effected in the usual
manner, the gripping plates being slackened to allow the strings to answer to the '
pull of the Wrest pins.-When the strings are tuned up, the clamping plates must
be screwed down, and caused to clamp the strings and hold them firmly upon the
plank bridge. The Wrest pins will thus be practically relieved from the constant
strain of the strings, and their tendency to become loose in the Wrest plank will
be avoided.
We may remark that the invention is applicable to pianofortes having a wooden
plank bridge, as the bridge may be faced by metal plates to ensure a proper grip
of the strings between metallic or unyielding surfaces.
Dated this 22nd day of August 1885.

page_text: We FRANK COLLINS and HARRY COLLINS, both of 43 James Grove, Peckham
in the County of Surrey, Gentlemen, and GEORGE WHEELER of 9 Cloudesley
Square, Islington in the County of Middlesex, Gentleman 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 object of this invention is to remove the tendency which the strings of
pianofortes have, to drop out of tune, which tendency is due to the "give" of the
wrest pins under the strain of their respective strings.
In attaining this object, we utilize the plank bridge, over which the wires are
strained, not only as a support for the wires, but as a holdfast in conjunction with
overlying gripping plates.
Supposing the plank bridge to be made of cast iron (as is usual), we level it in
the usual manner; then, by means of a file or otherwise, roughen the surface, to
prepare it to receive the strings.
' 27-
To this bridge we apply a series of gripping plates, some six inches in length,
more or less, which extend across the instrument, and serve to cover all the
strings These plates we roughen on the underside, to obtain a good grip of the
metallic strings, and we secure the plates to the bridge by screws or nuts and bolts,
taking care that each plate shall bear evenly on the strings which it overlies, and
hold them firmly at tension.
In the Drawing we have shown the invention as applied to an upright piano-
forte, Fig. 1 being a front view of the plank bridge fitted according to this
invention, and indicating its position with respect to the wrest plank.
:
Fig. 2 is a front view, on an enlarged scale, of the bass end of the bridge and the
wrest plank; and
Fig. 3 is a cross section of the same, showing the position, of the gripped strings..
In these figures, A is the wrest plank fitted with wrest pins a for drawing the
metallic strings b to tension.-B is the metallic bridge, and CC are metallic plates,
which are made fast thereto by bolts c c. c c are steady pins fixed to and
standing up from the bridge, and entering holes made for them in the plates C.-
The bolts and steady pins are so arranged as to leave a clear course between them
for the strings b. To ensure a proper grip of the strings between the metallic
surfaces B and C, we not only roughen those surfaces after they have been levelled,
but we provide that the plates C shall each extend over a group of strings of the
same gauge; when, therefore, the gauge is broken, the continuity of the gripping
surface C will also be broken.
The tuning of the instrument is effected in the usual manner, the gripping
plates CC being slackened to allow the strings to answer to the pull of the wrest
pins a. When the strings are tuned up, the clamping plates must be screwed
down tight and caused to clamp the strings and hold them firmly upon the plank
bridge. The wrest pins will thus be practically relieved from the constant strain
of the strings, and their tendency to turn in the wrest plank, under the strain of
their respective strings, will be avoided.

page_text: Fig. 4 illustrates a modification in the means for fixing the gripping plates to the
bridge. In this example, instead of using steady pins and screw bolts, we fit the
bridge face with screwed studs c, which pass through holes made to receive them
in the plate C, and we fit to these screwed studs, nuts c¹, which, when tightened
up, will hold the gripping plates firmly in place.
We may remark that the invention is applicable to pianofortes having a wooden
plank bridge, as the bridge may be faced by metal plates, to ensure a proper grip
of the strings between metallic or unyielding surfaces; or the wooden plank bridge
may be removed and replaced by a bar of metal.
This modification is shown in the cross section Fig. 5, where B is the bridge,
secured by countersunk screws to the wrest plank A, and serving to hold the
metallic strings between it and the gripping plate C.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
Relieving the wrest pins of pianofortes of the strain of the strings, by gripping
the strings between the bridge and gripping plates, as and for the purpose above
described.