AN IMPROVED PEDAL-HARP WITH DOUBLE ACTION
Year: 1883

page_text: LETTERS PATENT to Herbert John Haddan, of Kensington, Middlesex for
an Invention of AN IMPROVED PEDAL-HARP WITH DOUBLE ACTION a commu-.
nication to him from abroad by Erich Meyer and Company, of Braunschweig,
in the German Empire
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at
the Office of the Commissioners of Patents on the 8th May 1883.
HERBERT JOHN HADDAN, of Kensington, Middlesex, "AN IMPROVED PEDAL-
HARP WITH DOUBLE ACTION," a communication to me from abroad by Erich
Meyer and Company, of Braunschweig, in the German Empire
This invention has for its object to enable the player to change the sounds of
the harp from C flat into C or Ċ sharp, D flat into D, or into D sharp and so on,
by means of simple mechanism.
For this purpose I place a pair of rolls or disca near the peg of each cord, each
disc having two pins which grip the cord when the disc is turned and thereby
shorten its acoustic length, the distance of the outer pin from the peg being such
that the shortening of the cord raises its sound one half tone, while the inner pin
is at such a distance from the peg, that it raises the sound of the string a full tone,
when the string is gripped by its pins.
The outer or upper rolls are connected with eachother through all the octaves
by means of levers and a connecting rod that they make simultaneously the same
angular motion, and the inner or lower rolls are connected with eachother in a
similar manner, so as to make the same angular motion.
For moving the connecting rods I use for every single tone of the octave a
pivoted sector communicating at one end with the pedal and having near the other
end two curved grooves, each of which receives a pin attached to an oscillating
lever to which is hinged one of the connecting rods. The two grooves are partly
concentric with the fulcrum of the sector and partly excentric, in such a manner
that, while the concentric portion of one groove slides over its pin and leaves the
latter stationary, the excentric portion of the other groove slides over the second
pin and draws the latter to and fro.
The forward motion of each sector is produced by a pedal, while the return
motion is produced by a spring.
i

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Herbert John Haddan in the Great Seal Patent Office on the
8th November 1883.
HERBERT JOHN HADDAN, of Kensington, Middlesex "AN IMPROVED PEDAL-
HARP WITH DOUBLE ACTION," a communication to me from abroad by Erich 5
Meyer and Company of Braunschweig, in the German Empire
In order to be able to play a chromatic scale on a diatonic harp, either new
strings must be interposed, for which there is no place or a mechanical contrivance
must be applied to the same, whereby the existing strings of the harp may be so
altered as to procure the required semitones.
'
Figs 1-3 of the annexed drawings represent a mechanism which enables the
player by means of a mechanical shortening of the strings to raise at the same
time and through all octaves every tone of the harp tuned C flat major a half or a
full tone.
The player is thus enabled by means of a mechanical contrivance to change all
C flats into C or also into C sharps
D flats into D or also into D sharps
E flats into E or also into E sharps
F flats into F or also into F sharps
G flats into G or also into G sharps
A flats into A or also into A sharps
B flats into B or also into B sharps
1
]
The whole device comprises 7 single mechanisms of the same construction and
working, and corresponding to the 7 tones of the scale. From Figs 1 and 3 it
may be seen, that every string crosses a couple of rolls E E' placed beneath the 2
string, and then passing over a tension pin 8, is strained by a peg w.
The rolls shown in Fig 1 over the whole mechanism are secured every one to a
separate pivot, and are so constructed, that on being turned they grip by means of
2 pins the string exactly so that the pitch is raised half a tone by the operation
of the upper rolls, and a full tone by the operation of the lower rolls.
These rolls of all tones of the scale, or more precisely the pivots on which they
are fastened, are connected to one another through all octaves by means of
cranks e, e', Figs 1 and 4, and of connecting pieces, in such way that by pulling the
latter, the rolls always make the same angular motion.
At every turning of the rolls, the pins, being placed rectangularly to the free
strings, are turned into a vertical position, that is, parallel to the strings, in which
position they pinch the strings in such way that henceforth the latter, swinging
from the lower pin of every roll, have their pitch raised half a tone by the turning
of the upper roll, and raised a full tone by the turning of the lower roll.
This turning of the rolls is effected by a separate pedal P for every tone of the
scale, which pedal in its angular movement is exactly limited by 3 stops, this
movement being transmitted upward by a connecting rod enclosed in the column
of the harp (Fig 3).
The pedal and connecting rod being in their highest position, see O Fig 3, all
rolls are in their position of rest, that is, their pins do not touch the free strings,
but are in a rectangular position to the same, as well as to all drawn out strings.
By the movement from 0 to M of the connecting rod and pedal, the upper roll E
is turned through a right angle, whereby the pins grip the strings and raise their
pitch a half tone; these strings are indicated by broken lines (dot and dash). .

page_text: If the pedal is lowered another degree, the pins of the under rolls E¹ pinch the
strings in a corresponding manner and raise their pitch again half a tone, so that
the strings now are raised a full tone (these strings are indicated by uniformly
dotted lines).
The centre of gravity of this movement lies in the eccentric C represented in
Fig 4, which eccentric is connected to the pedal P by a rod and has an angular
movement corresponding to the degrees or stops and to the pedal movement.
This eccentric C contains two curved grooves f and in which slide two pins h i
fixed on levers A and B.
By the motion of the pedal from O to M, the eccentric makes the corresponding
movement O M, guiding the, pin' h in the curve to h', whereby the lever A is
led round pivot a to A', and the cranks e are led from O to M, whereby all rolls E
connected with these parts are turned, so that their pins grip the strings.
During this movement the lever B, whose pin till then has been guided in the
concentric part of curve g, remains unmoved. By the motion of the eccentric
from M to U, the pin his guided in the concentric part of curve f, that is, lever A
remains in its position A', whilst pin i slides in the corresponding curve of the
eccentric, thereby causing lever B to swing round pivot e and drawing it to B¹,
turning at the same time the pivots connected therewith in such a way, that the
corresponding under rolls grip the strings and change their pitch half a tone.
During the return motion of the pedals always effected by spring F (Fig 3),
the above indicated movements are made in inverse order, whereby the rolls return
to their primitive positions, that is to those corresponding to the play.
CLAIMS.
In pedal harps with double movement:
1. The use of an eccentric C with curves f, g, for every single tone of the octave,
and of the pins h, i, sliding in curves f, g, in combination with levers A, B,
oscillating round points a, b and bearing pins h, i.
2. The movements independent one from the other of the upper and the under
rolls E, E¹ produced by the arrangement of curves f, g on C.
3. The method of acting simultaneously on the 7 tones of the scale by means of
the levers A and B and their connection with the roll pivots.
In witness whereof I the said Herbert John Haddan have hereunto set my hand
and seal this 8th day of November A.D. 1883.
דרי חח