Year: 1887

page_text: Date of Application, 10th Dec., 1887
Specification Accepted, 2nd Mar., 1888
A communication from abroad by JOHANN GERHARD GOTTFRIED SCHMIDT, of
Köpnick, near, Berlin, in the Kingdom of Prussia, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for Foreign Patent
Solicitors 6, Lord Street Liverpool and 6, Bank Street. Manchester both in the County
of Lancaster, and 323 High Holborn in the County of Middlesex, Civil Engineer, 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 present invention relates to a piano which can be played either by hand in the
usual manner by striking the keys, or automatically, by turning a drum or cylinder
provided with pins on its periphery.
The invention consists essentially in the application of a new method of striking the
strings, the hammers being actuated not as usual by a blow directed against the
strings, but by a back pull; the invention further consists in the peculiar mechanism
for producing this back pull when the piano is played automatically, which back pull
acts directly upon the hammer nut, and aided by the action of a spring, throws the
hammer against the string. The piano action for playing by hand in the ordinary.
manner is similar to that adopted in other pianos, so that the player has not to
overcome any greater resistance than that experienced hitherto. In consequence of
the peculiar arrangement of this back pull, it is possible to employ shorter and
consequently more durable pins, and by a slight manipulation, to cause the hammers
to strike powerfully on the strings.
The invention is best described by aid of the accompanying drawings in which—
Figure 1, shows the piano action in the position required for playing by touching
the keys with the hands.
Figure 2, shows the automatic piano mechanism brought into action, whilst that for
playing by hand is out of gear.
The piano action can be of any suitable kind and is formed in the arrangement
illustrated in Figure 1, by the hopper A the jointed hammer nut B, and the hammer C.

page_text: By striking a key on the key board D, the hammer C resting on the hammer rail or
rest E is thrown as usual against the string G which then sounds. Between the
piano mechanism and the strings pass the rods H H pivoted at a the upper part of
his rod is connected to the hammer nut B by means of the small tie b, which passes
rough the eye in wire c. The lower end of the rod is formed inte a lug or plate
and passes through the rail or support I. In the flat part H' of the rod H is fixed a
tooth which (according to the position of H H¹) comes, or does not come in contact
with the pins on the surface of the drum K.
Figure 2 represents the tooth in contact with the pins on the drum.
Figure 1 represents the tooth moved clear of pins.
When the piano is played by hand by touching the keys, the mechanism for
automatic playing is thrown out of gear (Figure 1).
The hammer C strikes the string G when the key is depressed, and the tie b between
rod H and wire c is slack. The hammer is therefore moved forward without affecting
the position of rod H. If the drum K is turned by the crank L, and worm wheel M,
the pins on the periphery of the drum do not strike against the tooth d. Consequently
the rod HH is not affected by turning the drum K. The piano can then be played
just as usual without the mechanism for automatic playing causing any difficulty in
the performance of the player.
When the piano is to be played automatically the rail N is pulled back and thereby
the rod HH turned on its pivot by the spring, in such a manner that the tooth d
conies within the reach of the pins on the drum K.
Whilst the rod HH' turns thus, the tie applied at the upper part H draws the
hammer nut B towards the strings, thereby raising the hammer C from the rail E on
which it rested, and brings the said hammer at such a distance from string G that the
vibrations of the latter do not reach it. If, whilst the barrel K is revolving, one of
the pins on the latter meets the tooth d on H¹ the latter will, notwithstanding the
tension of spring O, be turned away from the barrel whilst at the same time rod H is
turned forward, and the hammer brought to rest on rail E, that is to say, it answers
the position shown in Figure 1.
As soon as the pin on the barrel has slipped over the tooth d of plate H³, the said
plate is brought back again by the action of spring O, (Figure 2) the rod H exerts
through the medium of the tie b a pull on the hammer C, by which the said hanımer
is thrown forward and strikes the string G. When this is done the hammer resumes
the position shown in figure 2 until another pin of the barrel K strikes the tooth d
and thereby gives the hammer its initial motion, and then a striking motion. The
strength of spring O determines therefore the force of the blow, and as the force of
the blow depends upon the tension of the spring, this tension can be increased by
lengthening the pins. It is therefore possible by giving the proper length to each
pin to increase the sound of the instrument to the extent required. As has been
before described for mechanical or automatic playing of the instrument neither the
piano action nor the keys are moved, but only the hammers, which are set in motion
by the tension of a comparatively weak spring. It therefore follows that the pin
barrel K can be turned easily, and the wear and tear of the pins is very slight. There
is another very great and important advantage, however, arising from the arrangement
of back pull, namely, the motion imparted by the barrel pins through the long lever
formed by the rod HH to the haminer C or hammer nut B; the pivot or fulcrum of
the rod HH can be so chosen that a very small motion of the plate F is only
requisite to give to the hammer C the necessary impulse under the development of the
requisite force. The consequence of this arrangement is that the smallest possible
length of the roller pins will effect sufficient throw. A greater number of pins lying
on one circle may therefore be used, that is to say it is possible to cause a barrel to
play a piece of music longer than what is usually played by other barrels of the same
periphery which have hitherto been used.
The following are some of the advantages of the invention
1. The piano can be played by hand by striking the keys in the ordinary way, and
this is in no wise impeded or influenced by the mechanism for automatic playing.

page_text: 2. Pin barrels of a smaller diameter can be used for playing longer pieces of music,
and thereby, the space left under the keyboard can be utilized, without its form being
altered.
3. Shorter barrel pins can be used, and consequently greater security against the
pins becoming bent or worn.
4. The sound can be increasel without materially affecting the number of pins
applied on the circumference of the barrel.
5. The cost of manufacture is reduced, as the automatic playing mechanism is the
simplest that can be conceived.
6. Any existing kind of piano action can be altered into an automatic one.
Having new particularly described and ascertained the nature of the said
invention and in what manner the same is to le performed as communicated to me
by my foreign correspondent, I declare that what I claia is :-
1. In nechanical pianes and similar stringed instruments the method of striking
the strings by means of laminers under the tension of springs, instead of the usual
manner of striking them by pressure on the hammers substantially as and for the
purpose described.
2. The means of carrying into effect the method described in claim 1, consisting of
the arrangement of a rod H, capalle of turning on a pivot or fulcrum, and submitted
to the tension of a spring which rod is placed between the piano action and the
chord G, and has its upper end connected to the hammer nut B, or hammer C, itself
by the tie b, and carries on its lower cul H', a tooth , which is acted upon by the
teeth or pins of the barrel K, substantially as described.
Dated this 9th day of December 1887.
WM. P. THOMPSON & Co.,
Agents for the Applicant.