Improvements in the Construction of Upright Pianos.
Year: 1892

page_text: Date of Application, 7th Mar., 1892
Complete Specification Left, 17th Nov., 1892-Accepted, 21st Jan., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Upright Pianos.
I CHARLES HAMPTON of 139 Barry Road Dulwich S.E. in the County of
Surrey Pianoforte Manufacturer do hereby declare the nature of this invention to
be as follows:-
The object of this invention is an improvement of my Patent A.D. 1888
5th March, No. 3386 by two additions and three alterations, viz. instead of the
metal rabbet (a 3 Fig. 5) being flush with front edge of metal bracings I bring the
metal rabbet forward Hush with front of wrest plank (d. Fig. 1) and elongate
the same to the extreme treble, level with treble end of hitch pin plate (c. Fig. 3)
for the double purpose of adding a front projecting treble bar flush with front edge
of metal wrest plank rabbet and connecting the two in one casting thereby
increasing the depth and length of metal wrest plank rabbet and strengthening both
the treble end of hitch pin plate and wrest plank and improving the tone
particularly in the treble part of the piano.
In place of a bevilled hitch pin plate (c. Fig. 3) I place a fint plate with
projecting rim on the inner edge extending to and connected with the above named
projecting treble bar.
Instead of the base plate with recesses (a and a 1 Fig. 3) I substitute a bottom
plate plain on the top side without recesses and turn the flange in which the hitch
pins are fixed see (Fig. 5) outwards instead of inwards thus gaining an inch longer
strings as well as facilitating and improving the fixing of both the wood bracings
and the sounding board.
I alter the cross section of metal bracings (Fig. 6) both above and below the
lower edge of wrest plank (d 2 Fig. 1) making the front edges (a 2 Fig. 3) narrower
below the wrest plank to reduce the surface near the belly and considerably
strengthen the metal bracings above that line the better to sustain the
overpull of the strings which hitherto have been inadequate owing to the metal
bracings (a 2 Fig. 5) being the same thickness throughout and being notched out
at a 3 Fig. 5 makes that part the weakest which in practice I find should be the
strongest.
Dated this 7th day of March 1892
COMPLETE SPECIFICATION.
Improvements in the Construction of Upright Pianos.
1 CHARLES HAMPTON of 139 Barry Road, Dulwich S.E. in the County of
Surrey, Pianoforte 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:-
The object of this invention is an improvement of my Patent dated A.D. 1888,
5th March, No. 3386 by two additions and three alterations, viz.: instead of the
metal rabbet (marked a, Fig. 5, in the said former Specification) being flush with the
front edge of the metal bracings, I bring the metal rabbet forward, flush with
the front of wrest plank (marked d, Fig. 1, in the said former Specification) and
clongate the same to the extreme treble, level with the treble end of hitch pin
plate (marked c Fig. 3 in the said former Specification) for the double purpose of
adding a front projecting treble bar flush with the front end of metal wrest plank
rabbet and connecting the two in one casting thereby increasing the depth and
[Price 8d.1

page_text: length of the metal wrest plank rabbet and strengthening both the treble end of
hitch pin plate and wrest plank and improving the tone particularly in the treble
part of the piano.
In place of a bevilled hitch pin plate (c, Fig. 3) I place a flat plate with projecting
rim on the inner edge extending to and connected with the above named projecting
treble bar.
Instead of the base plate with recesses (a and a Fig. 3) I substitute a bottom
plate, plain on the top side without recesses and turn the flange, in which the hitch
pins are fixed (see Fig. 5) outwards instead of inwards thus gaining an inch longer
strings as well as facilitating and improving the fixing of both the wood bracings
and the sound board.
I alter the cross section of metal bracings (Fig. 6) both above and below the
lower edge of wrest plank (d2 Fig. 1), making the front edges (a² Fig. 3) narrower
below the wrest plank to reduce the metal surface near the belly and considerably
strengthen the metal bracings above that line the better to sustain the over-
pull of the strings which hitherto have been inadequate owing to the metal
bracings (a Fig. 5) being the same thickness throughout and being notched out
at a³ Fig. 5 makes that part the weakest which in practice I find should be the
strongest.
The foregoing reference figures, and letters have reference to the aforesaid
former Specification.
DESCRIPTION OF THE DRAWINGS.
Figure 1, is a transverse section of my improved wood back with metal stiffening
piece taken about the line A-A Fig. 2.
Figure 2 is a front view of Fig. 1.
Figure 3 shows by front view the metal frame separately and
Figure 4 is a side view of the same.
Figure 5 shows by front view to an enlarged' scale one of the metal bracings a³.
Figure 6 is a similar view to Fig. 1, but on a larger scale; and shows the form of
cross section of one of the metal bracings below the wrest plank rabbet.
Figure 7 is a cross section on the line B-B Fig. 6, showing the form of one of
the metal bracings above the wrest plank rabbet.
Figure 8 is a cross section through the hitch pin plate taken on line C-C Fig. 3
but on a larger scale than that figure.
a is the base plate, with plain top side which supports the lower ends or feet of
the wood bracings b; the latter being secured by bolts b. a is the outwardly
turned flange,, of the base plate a, upon which the hitch pins are fixed.
Cast in one piece with the bottom plate a is a hitch pin plate c, with projecting
rim c' in place of a bevelled or ordinary flat plate, the sharp edge c' serving the
purpose of localising the vibrations or stopping the vibrations from running over it
and thereby helping to insulate the sound from the metal frame, cast in the same
piece as the bottom plate a and hitch pin plate care vertical bracings a² a², the
whole casting forming the framing which takes the strain of the strings from
treble to bass, and forming also the foundation upon which the wood back is
built up.
In order to resist the vertical strain or "down pull" of the strings a deep metal
rabbet a is formed near the upper end of the bracings a² and is made flush with the
front of the wrest plank and elongated to the extreme treble level with the treble
end of the hitch pin plate c, the two being connected in one casting by the treble
bar a*.
1
Upon the metal rabbet a³, separated by woollen cloth or other suitable sound
insulating material, is supported the wiest plank d secured by bolts e to the metal
frame, to resist the "overpull" of the strings.
The wrest plank dl construct in two separate parts, d', d, of different
thicknesses.

page_text: The thicker part d', which is supported on the rabbet a', receiving the wrest
pins and bearing the tension of the strings, is connected to the wood bracings b by
means of intervening wood blocks placed at the whole being secured by bolts i i.
The smaller portion of the wrest plank d forms the support for the upper end of
the belly or sound board h, and is connected to the larger blocks 6 by means of
smaller blocks b³.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein before described improvements in the construction of upright piano-
fortes consisting of the modified form of front projecting rabbet a³ elongated to the
extreme "treble" and connected to the hitch pin plate by the treble bar or flat
plate a with projecting rim on its inner edge, base plate with plain top side without
recesses and outwardly turned flange, and modified form of bracings arranged and
combined all as and for the purpose set forth.
2. The hereinbefore described modifications of the parts of upright pianofortes as
set forth.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.