Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1911-01-04
PIANO HAMM ERS.
Various Sizes in Set Are Made to
Grade Accurately.


Grade Accurately.
Piano hammers are made of core
of wood with a felt face. Looked at
as they stand in an even row the ham,
mers in piano appear to be all alike.
but really both as to the size of the
wooden core and the thickness of the
felt covering they are graded in size
and weight, from the heavier ham
mers that strike the bass strings at
one end OF the piano down to the
lighter hammers that strike the light
err treble wires at the other.
1t might seem that it would be very
difficult to grade the hammers with
the perfect accuracy required. and it
would in fact be next to impossible to
do so if they We're made and assem-
bled separately; but the hammers of
a piano are made all at onee-they are
originally all OF d piece; and the man
ner of their manufacture is such that
they could not do otherwise than
grade with accuracy.
Formerly only mahogany was used
for the core of piano hammers; now
there are used also walnut and birch,
wood. Whatever the wood it must be
fine and straight grained and fiaWless
and perfectly seasoned.
A strip of such wood six or eight
inches longer than is required to make
the total number of hammers is run
through a machine that moulds it into
the shapes required for the hammer
cores in cross section this strip being
thick at one end and tapering to the
other end. This piece of moulding is
finished and polished and then it is
ready To be sawed up into separate
cores.
When the core moulding has been
sawed up the side faces are smoothed
and polished, and then the cores are
closed up together and held together
rigidly and exactly in line by clamps.
Then there is put on these cores, in
one strip, what is called the under
felt, this being OF uniform thickness
from end TO end of the set of cores.
Then the hammer cores are ready to
receive the outer felt. the hammers
face.
At one time the varying degree OF
thickness OF felt covering was made
by putting on fewer or more layers of
felt, now the grading in the thickness
required on the hammers is accom-
plished with absolute accuracy by the
use of felt specially made for the pur-
pose.
Felt for this use is made in sheets
between three and four feet square,
such sheets being of about one inch in
thickness along one edge, and tapering
to perhaps quarter of an inch in
thickness at the opposite edge
From one of these sheets there is cut
for the outer felt OF the hammers
strip about three inches in width, cut
OFF down the wedge, from the thick end
TO the thin, the thick end to go around
| the big cores and so on along with the
thin end around the little cores, this
thick strip to be bent around the ham
mer cores just as the thinner under felt
was. To make this possible the long.
thick strip of felt is beveled off for its
entire length from the middle line
down to either edge.
| This outer felt, with the beyeled
edges inside against the cores, is glued
on and pressed on in a mould over the
under felt, and the set of cores with
their felt covering is complete. In this
shape the set of cores look like a tap
ering moulded strip of wood with one
edge covered with tapering rounded
covering of felt.
| Then the felt on the hammers, still
clamped together as they are is finally
cleaned and finished, and then with a
sharp knife, by hand, the hammers are
cut apart. Glued under pressure as
they are the felt would be likely to
stay on the cores indefinitely, but to
prevent the possibility of their coming
off in any climate each felt hammer
covering is wired on to its core bv a
stitch of wire taken through felt and
| core from side to side. Then in tn,
heel of each core is bored hole to re-
| ceive the hammer shank. by which the
hammer will be attached to the pianos
action; and there's your set of piano
| hammers all complete and ready to go
into a piano.
There are piano factories in which
pianos are made complete in every
! part, including the hammers, and there
are factories in which some of the
parts used are bought of manufacture
ers who specialize in the production of
| one part or another. Thus there are
factories in which are made piano
hammers exclusively.
There are made in this country an
nually about 100000 pianos A set of
piano hammers numbers eighty eight,
so to equip the pianos made here there
are annually required somewhere abou,
100000 piano hammers.-New York
Sun.