Year: 1898

page_text: Date of Application, 29th Jan., 1898-Accepted, 26th Mar., 1898
I, JULIUS SCHÜTZE, of No. 153, Köpnickerstrasse, Berlin, in the German Empire'
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 the present application for Letters Patent consists of a repetition
mechanism for pianofortes which enables a player to strike a note as many times as
desired consecutively without allowing the key to return completely to its original
position.
The invention is illustrated by way of example in the accompanying drawing,
in which
Figure 1 shews the mechanism in the position of rest.
Figure 2 shews the position of the parts with relation to one another when the key
is fully depressed, and the hammer is in contact with the string.
Figure 3 shews the position of the parts when the key is in a somewhat depressed
position and prepared to repeat.
The parts essential for the repeating action are not necessarily connected to a
mechanism such as that illustrated in this drawing. They are capable of being
applied to any desired action, whether the same be constructed long or short, or
with upper check action or lower check action. The double arm key lever A has its
centre of revolution at the point A¹. By means of a piece A2 attached to it, it presses
against the reinforced longer end of a single arın lever B, which lever revolves on B¹.
The said pivot B¹ is attached to the support C. The bar F is jointed to B close to
its free end. This bar F has the form of an unequal arm angle lever, the longer arm
of which is directed upwards, whilst its shorter arm F2 comes in contact with the
regulatable piece H secured to the cross piece G. The pins P serve to guide the bar F
on each side. The shorter lever arm F2 possesses at its end in the mechanism here
shewn by way of example a fork which, when the key is depressed, actuates the
damper mechanism and raises the damper from the string Dx. In the position of rest
the point of the bar F engages under the boss I, which has its centre of revolution
secured to the frame piece C¹, and which boss bears the hammer I. The said hammer
rests when out of action against the cross piece K. A weak spring L strives to bring
back the har F and the boss I into the position shewn in Figure 1. It is obvious that
felt and leather cushions are provided at such points where friction is encountered, or
where wood strikes against wood. If the key A be depressed at its free end, not
shewn in the drawing, its inner end A rises, presses against the end of the lever B
and moves the same upwards. Consequently as the bar F is united to B it must also
participate in this upward motion, and as its point. engages in the hammer boss I,
and this latter is revolubly attached to the cross piece C¹, it must receive a turning
motion because it cannot escape it in the direction of the thrust. As the hammer I¹
is connected to the said boss I it must follow its motion, and owing to the length of
its shaft it will be propelled with considerable quickness against the string. When
the upward motion of the mechanism has reached its limit, the shorter lever arm F
rn... 631

page_text: of the piece F comes in contact with the part H. The point F1 of F separates from
the boss I if the upward motion proceeds further. The momentum which is possessed
by the hammer is sufficiently great to cause it to strike the string. The centre of
gravity of the hammer when in the striking position does not pass beyond the
perpendicular drawn through its centre of revolution; consequently its own
Moreover this is
weight will cause it to fall back into its original position.
strengthened by the rebound which the hammer head experiences from its blow on
In order to prevent
the elastic string, and also through the action of the spring L.
this backward motion from continuing until the haminer rests on piece K the following
arrangement is devised.
From the hammer boss I procceds a pin M which bears a hammer shaped down-
wardly projecting head M¹. Upon the bar F is attached by means of a spring Na
block N¹. This block encounters the backward motion of the head M¹, and
consequently that of the hammer I¹.
It has been already pointed out that the backward motion of the hammer takes
place with some considerable force; the surface of M¹ will consequently slide a little
over the rounded surface of N¹. By this means the spring N receives a certain amount
of compression. If the key be released a little without allowing it however to return
completely to its position of rest, the piece N' together with the whole mechanism will
move downwards a little, and M¹ and consequently the hammer I¹ must share in this
motion. The point of the bar F which was hitherto out of contact with the boss I, is
thereby pressed under the notch of the said boss by means of the expanding spring N,
and the whole mechanism is again ready to act (Figure 3); consequently it only
requires a repeated depression of the key out of the above described intermediate
position in order again to propel the haminer against the string.
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 :-
In a piano mechanism :—
The hereinbefore described repeating mechanisın characterized essentially by the
arrangement that the rounded block N' attached to the end of a spring N secured to
the back of the bar F allows to slide over it the hammer shaped head M¹ (downwardly
directed) of the boss I, when the hammer 1' returns after the blow into its position of
rest, whereby the spring N is somewhat stretched so that upon a slight release of the
key the point F of the bar F is again brought into contact with the notch of the
hammer boss I, and the repetition of the note is rendered possible without allowing
the key to return to the original position of rest, substantially as described.
1909
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.