proved Means for Covering Pianoforte Hammers.
Year: 1897

page_text: Date of Application, 19th Jan., 1897
Combiete Specification Left, 19th Oct, 1897--Accepted, 20th Nov., 1897
PROVISIONAL DT EUITIATION
Improved Means for Covering Pianoforte Hammers.
I, CHARLES HARRISON, of 53 Archer Street, Pratt Street, Camden Town, in the
County of London, Pianoforte Hammer Coverer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to the covering of pianoforte hammers and comprises an im-
proved construction of the moulds used in the manufacture of pianoforte hainmer-heads,
and improved means for drawing or clainping together the sides of such moulds.
In the apparatus hitherto used for the above-mentioned purpose, the upper parts
of the sides of the mould are simply hooked under a projection on the lower portion
of the mould, and, after the felt and the wooden heads have been pressed into the
lower portion of the mould, the said upper parts are brought together and are then
pressed against the sides of the hammer-heads by means of a number of separate
clamps, the application of which takes a considerable time, often allowing the glue to
become chilled or cooled so that the felt and wood used in forming the hammer-head
will not properly adhere together.
Now according to one part of my said invention I provide improved means whereby
the said upper parts of the sides of the mould can be brought together and pressed
against the sides of the hammer-heads much more rapidly and effectively than
heretofore.
For this purpose I employ screws which are passed through holes in bosses formed
in the upper parts, of one side of the mould. On the upper part of the other side of
the mould I form bosses having holes extending through them and each having a
recess in which is placed a portion or segment of a screw-nut. After the felt to be
used in making the hammers has been laid upon the lower portion of the mould, and
the wood portions of the hammer-heads have been pressed on to the felt and into the
lower portion of the mould, the upper parts of the sides of the mould are brought
together by hand or in any other suitable manner and are then pressed tightly
against the sides of the hammer-heads by means of the said screws. The nut-segments
placed in the recesses above mentioned, are free to rise through a short distance
to permit the threaded part of the screws to pass under them, so that the sides of the
mould may be brought together quickly. Instead of making the screw with an
ordinary V-shaped screw-thread, I make it with an undercut and backwardly inclined
screw-thread, so that, when the sides are thus brought together, the screws will
readily push upward the said nut-segments. The nut-segments will then fall into
engagement with the threads of the screws and the tightening up can be rapidly and
effectively performed by means of the said screws. The advantage of using the
slip-nuts above mentioned is that the sides can be brought together and tightened
up far more rapidly than heretofore, and before the glue has cooled, thus ensuring
adherence of the felt to the wooden parts of the hammer-heads.
According to my said invention I also improve the apparatus by so constructing
it that the inovable sides of the inould cannot fall off and so as to resist the pressure
of the top. For this purpose the said movable sides are pivoted at or near their lower
edge to the lower portion of the mould, metal rods or bars extending through the

page_text: entire length of the mould and serving as hinge-pins.
This method of constructing
the mould is much more advantageous than the old method of hooking the movable
sides under the edges of the lower portion of the mould. The two halves of the
lower portion of the mould are held together by suitable screws through the sides.
.
Dated the 19th day of January 1897
I, CHARLES HARRISON, of 53 Archer Street, Pratt Street, Camden Town, in the
County of London, Pianoforte Hammer Coverer, 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:-
My invention relates to the covering of the heads of pianoforte-hammers with felt
or the like, and comprises improved means for drawing or clamping together the
sides of the moulds used for this purpose.
In the apparatus hitherto generally used for the above-mentioned purpose, the
upper parts or sides of the mould are simply hooked under a projection on the lower
portion of the mould, and, after the felt and the wooden heads have been pressed into
the lower portion of the mould, the said upper parts or sides are brought together and
are then pressed tightly against the sides of the hammer-heads by means of a number
of separate clamps, the application of which takes a considerable time, often allowing
the glue to become chilled or cooled so that the felt and wood used in forming the
hammer-head will not properly adhere together. Consequently heat has to be
applied to the mould.
It has been proposed to connect the sides of the mould to
the lower portion thereof by means of pivot-pins and to employ screws and nuts or
hand-wheels for drawing together the sides of the said mould; but these means
do not permit of the sides being pressed against the hammer-heads quickly enough
to cause the felt to adhere to the wood without the application of heat.
Now according to my said invention I provide means whereby the said upper parts
or sides of the mould can be brought together and pressed tightly against the sides
of the hammer-heads much more rapidly and effectively than heretofore.
For this purpose I employ screws which are passed through holes in bosses formed
on one of the upper parts or sides of the mould; and on the other upper part or side
of the mould I form bosses having holes extending through them and each having a
recess or recesses in which is placed one or more portions or segments of a screw-nut.
After the felt to be used in making the haminers has been laid upon the open mould
and the wood portions of the hammer-heads have been pressed on to the felt and
forced therewith down into the lower portion of the mould, the upper parts or sides
of the mould are first rapidly brought together by hand or in any other suitable
manner and are then pressed tightly against the sides of the hammer-heads by means
of the said screws. The nut-segment or nut-segments placed in the aforesaid recess
or recesses are free to rise or move through a short distance away from the axis of the
screw to permit the screw-threaded part thereof to pass under or between the same,
so that the sides of the mould may be brought close together very quickly. Instead
of making the screw with an ordinary V-shaped screw-thread, I sometimes make it
with an undercut and backwardly-inclined screw-thread, so that, when the sides are
thus brought together, the screws will readily push upward or outward the said
nut-segment or nut-segments. The nut-segment or nut-segments will then fall or

page_text: move back into engagement with the thread of the screw and the tightening up can
then be rapidly and effectively performed by turning the two screws about their axes.
The advantage of using the aforesaid slip-nuts or nut-segments is that the sides can
be brought together and tightened up far more rapidly then heretofore, and before
the glue has cooled, thus ensuring the effectual adherence of the felt to the wooden
parts of the hammer-heads without the application of heat.
The said movable sides are preferably pivoted at or near their lower edge to the
lower portion of the mould, by means of metal rods or bars extending through the
entire length of the mould and serving as hinge-pins or pivot-pins.
In the accompanying drawing
Figure 1 is a plan, partly in horizontal section, showing a mould with my
improvements applied thereto.
Figure 2 is a vertical section on the line x, x, Figure 1, drawn to an enlarged scale,
showing the mould open, and the felt in place to receive the hammer-heads.
Figure 3 is also a vertical section on the line x, x,. Figure 1, drawn to an enlarged
scale, showing the mould closed tightly upon the hammer-heads.
Figure 4 is a vertical section on the line x¹, x¹, Figure 1, drawn to an enlarged
scale.
a is the lower portion of the mould, which consists of two parts firmly bolted
together. b, b¹ are the upper parts or sides of the mould, which are pivoted to the
lower portion a by means of rods, c extending from end to end of the mould and
passing through lugs 62 on the sides b, b¹. Two screws or bolts d are passed through
elongated holes or slots in the end lugs b³ of the side b¹ of the mould, and engage with
nut-segments e, e contained in tapered recesses f in the end of lugs 64 of the side b of
the mould. These nuts are tapered to correspond to the inclined walls of the taper
recesses as shown in Figure 4, and a cap g is secured upon each of the lugs 64 so as
to retain the said nuts or nut-segments in their respective recesses.
To prevent
relative displacement of the two segments of each nut e, e, the said segments are held
together by means of a pin passing freely into a hole in one segment and screwed into
a tapped hole in the other segment, or by other suitable means.
The bolts d are
adapted to receive crank-handles or hand-wheels for turning them about their axes
to apply the requisite pressure to the sides of the hammer-heads through the upper
parts or sides of the mould.
When the strip h of felt, with the glue applied thereto, has been placed upon the
open mould as shown in Figure 2, and the hammer-heads j, Figure 3, have been forced
therewith down into the lower portion a of the mould, the sides 6, 6' are to be rapidly
turned about the pivot-pins or rods c by hand, or preferably by means of a treadle-
lever suitably arranged in the press in which the mould is used, so as to fold the felt
over the hammer-heads, as shown in Figure 3. Then, by pushing the bolts & inward,
the nut-segments e, being moved towards the wider end of the taper recesses f, will
permit the said bolts to be thrust through between them, without turning the said
bolts, until the collars d' on the latter come against the lugs b³. The sides b, b¹ of
the mould can then be very tightly pressed against the hammer-heads by turning
the said bolts & a few turns about their axes until the nut-segments are thus drawn
into the narrower end of the said taper recesses as shown in Figure 4.
It is evident that, with the means above described, the requisite pressure can be
applied to the felt on the sides of the hammer-heads more rapidly than heretofore,
the bolts & sliding freely between the nut-segments for a considerable distance, and
the time that would otherwise be required to move the said bolts through such
distance by screwing or turning them about their axes, is thus saved and the
necessity for employing heat is obviated, as the glue has not time to dry before the
required pressure is applied.
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 :-
The improved means whereby I provide for the rapid application of the reanirod

page_text: pressure to the sides of the hammer-heads through the upper parts or sides of the
mould, substantially as hereinbefore described, and for the purpose specified.
Dated the 10th day of October 1897.
D. YOUNG & Co.,
11 and 12 Southampton Buildings, London, W.C.,
_ Agents for the Applicant.