IMPROVE- MENTS IN CENTRE OR HAMMER RAILS FOR PIANOFORTES
Year: 1884

page_text: I, CARI. ERHARDT, of 38 Brooke Street, Holborn, in the County of Middlesex,
Commission Agent, do hereby declare the nature of my Invention for "IMPROVE-
MENTS IN CENTRE OR HAMMER RAILS FOR PIANOFORTES " 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 centre or hammer rails of pianofortes and is
applicable for use with various kinds of pianoforte actions. Its object is to
strengthen the said centre or hammer rails and to render the same more rigid than
heretofore, and thus prevent the vibration or the warping of the same.
Centre or hammer rails have been heretofore made with a strengthening piece
secured to one side thereof, that is to say, with a metal plate or a piece of angle-
iron extending from one end to the other of the said rail and secured thereto in
any convenient manner. But according to my Invention I substitute, for this plate
or angle-iron, a piece of channel-iron or a bar or piece of steel or other suitable
metal of similar form, which bar or piece fits, and is secured in any convenient
manner, upon a longitudinal rib or projection on the said rail.
My said Invention is illustrated in the accompanying Drawing in which
Figure 1 is a transverse section of part of a pianoforte action showing one form
of rail with which my improvements are incorporated or embodied.
Figure 2 a side elevation of the said rail.
Figure 3 is a transverse section showing a slight modification thereof.
A indicates the centre or hammer rail, B B are the arms or brackets for
carrying the hammers C, and DD are the arms or brackets for carrying the
levers E for operating the said hammers. The centre or hammer rail A. is made
with a longitudinal rib or projection a, and upon the said rib or projection is fitted
the metal bar or piece F which is preferably a piece of channel-iron, but which
may be a piece of steel or other suitable metal similar in form to channel-iron,
that is to say, having a web f and two flanges f¹ projecting or extending in
the same direction from the said web at right-angles thereto or nearly so.
said bar is secured in place either by the screws Gas shown, or merely by the
engagement of its flanges f¹ with the sides of the rib or projection a.
T
The

page_text: In some cases I make the said rib or projection of different form in transverse
section to those shown in the Drawing.
By combining with the said centre or hammer rail, a bar or piece of metal made
in the manner above described, it is obvious that the strength and rigidity of the
said rail will be greatly augmented, as the flanges f¹ of the said bar offer great
resistance to any lateral stress caused either by the tendency of the rail to warp,
or otherwise.
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 combination, with the centre or hammer rail of a pianoforte, having a
longitudinal rib or projection as above described, of a piece of channel-iron or a
bar or piece of steel or other suitable metal of similar form fitted and secured
upon the said rib or projection, substantially as set forth.