Improvements in Grand Pianoforte Actions.
Year: 1890

page_text: Date of Application, 14th Aug., 1890
Complete Specification Left, 11th May, 1891-Accepted, 4th July, 189.
PROVISIONAL SPECIFICATION.
Improvements in Grand Pianoforte Actions.
I CHARLES JAMES COXHEAD, of 138 Iverson Road, Kilburn in the County of
Middlesex, Pianoforte Manufacturer do hereby declare the nature of this invention
to be as follows:-
-
Inconvenience arises in regulating the mechanism of grand pianofortes according
to systems at present generally in use.
Existing systems do not allow a key, or other part, of the said mechanism in
case of derangement, or requirement for adjustment to be withdrawn without
dislocating the framework of the upper part of the action which usually must be
all removed before access can be had to the rest of the mechanism.
This inconvenience is by my invention of detaching the check from the key
obviated.
Also by my invention the friction that occurs in the act of escapement is
lessened. The general arrangement of the improved apparatus, is as follows:-
The lever movement which acts on the hammer is affixed to a rail at the back
part of the action and works on a centre, the tail part of the lever extends beyoud
the centre and that part meets the check block the check is inserted in this
block which works on a centre that is fixed to the back part of the rail, the tail
part of the lever meets the tail part of the check block and causes the check to
rock up to its work and return by the action of the lever.
My improved escapement is constructed as follows:-
The front part of the lever contains the fly that acts on the hammer butt, and
in front of the fly a pillar is inserted in the lever, the pillar contains an escape-
ment button and screw pin for the purpose of regulation.
As the lever lifts the hammer to the string the escapement button gradually
it
approaches the fly and causes it to escape from the butt by pushing away.
Dated the 14th day of August 1890.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Grand Pianoforte Actions.
I CHARLES JAMES COXHEAD, of 138 Iverson Road, Kilburn, in the County
of Middlesex, 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 :-
Inconvenience arises in regulating the mechanism of grand pianofortes according
to systems at present generally in use.
Existing systems do not allow a key, or other part, of the said mechanism in
case of derangement, or requirement for adjustment to be withdrawn without
dislocating the framework of the upper part of the action which usually must be
all removed before access can be had to the rest of the mechanism.
This inconvenience is by my invention of detaching the check from the key
obviated.
Also by my invention the friction that occurs in the act of escapement is
lessened. The general arrangement of the improved apparatus, is as follows:-
:-

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 shews an arrangement of parts adapted for carrying out my invention, in
a state of rest whilst
Fig. 2 shews these parts as they appear when the key has been struck and the
finger kept thereon depressing it.
A is part of a key centred at A', the rest being broken away for convenience of
the drawing. is the hammer.
a the butt thereof centered to the rail b.
c is the front fly.
d is a spring at back of arm on lever.
fon which is centred the moveable fly e.
g is a cord between the screw hook of the flye and the tail of the hammer
butt a¹.
is the back rail.
kis the check mounted on the check block k¹.
is the pillar projecting from front end off to carry button .
The lever movement which acts on the hammer is affixed by an arm to a rail i
at the back part of the action and works on a centre, the tail part of the lever f
extends beyond the centre f' borne by an arm from the rail, and that part meets
the check block the check is inserted in the block which works on a
centre that is fixed to the back part of the rail, the tail part 2 of the
lever meets the tail part of the check block and causes the check k to rock
up to its work and return by the action of the lever.
My improved escapement is constructed as follows:-
The front part of the lever contains the fly that acts on the hammer butt, and
in front of the fly a pillar is inserted in the lever, the pillar / contains an escape-
ment button and screw pin carrying it for the purpose of regulation.
As the lever lifts the hammer a to the string the escapement button
gradually approaches the fly c, and causes it to escape from the notch a² of the
butt a¹ by pushing it away pressing on the part e
:
The repeat is produced by a spring d at the back part of an arm projecting
from the lever which acts in the first place on a moveable flye working in the
lever by a centre a silk cord g or other convenient substance is attached to a
regulating screw on the top of the said fly e and passes through the front fly c
that acts on the hammer a and is attached to the tail end of the hamuner butt a'
the cord is left a little slack when the hammer is at rest and tightens as the
hammer approaches the string (see Fig. 2) a regulating button then comes in
contact with a rail at the back and gives the required drop when the hammer is
driven into the check by the force of the blow as soon as it is released by raising
the key the repeat spring d directly tightens the cord and the front fly at once
returns to the notch a² of the hammer butt a'.
The escapement and repeat movements are most convenient to this action but
other kinds may be used without departing from the novel character of the
improvement in the movement and construction of the check and the way it is
acted on by the lever/.
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: In a grand pianoforte action the combination or arrangement of parts for
effecting the check of the hammers so that a key or keys may be withdrawn,
without dislocation or separation of the parts of the "action" substantially as set
forth.
2: In a grand pianoforte action the combination or arrangement of the check k,
lever, lever, pillar and button and parts operated thereby for effecting
control of the movements of hammer and its operative parts as set forth.
P

page_text: 3: In a grand pianoforte action the combination or arrangement of parts for
operating and controlling the movements of the hammer substantially as and for
the purposes herein before set forth.
Dated the 11th day of Max 1891
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.