IMPROVEMENTS IN ACOUSTIC OR MECHANICAL TELEPHONES
Year: 1885

page_text: COMPLETE SPECIFICATION;
We HENRY SELIGMAN and EMMA SELIGMAN, both of Irvington-on-Hudson in
the State of New York, United States of America Inventors do hereby declare the
nature of the said Invention for IMPROVEMENTS IN ACOUSTIC OR MECHANICAL
TELEPHONES and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Our invention relates to, and embraces a system of acoustic or mechanical
telephony and contemplates a transmitting and a corresponding receiving phone,
the line wire connection, ineans for centering and supporting and devices for
retaining the tension of the wire when turning angles, and all other necessary
accoutrements and parts for completing a system of practical telephony as afore-
said without employing electricity as the conducting agent.
Prior to our invention, hereinafter disclosed, no.thorough and efficient system of
acoustic telephones had been introduced, inasmuch as the difficulties encountered,
either in one respect or another, rendered abortive any attempt at such production
even on a small scale, and where the obstacles or impediments were reduced to a
minimum.
The purpose of our invention therefore, is to construct a phone of greater
sensitiveness (combined with great strength and durability) than any heretofore
employed and to eliminate, as far as possible, the harsh and metallic sounds which
attend and follow the direct connection of the line wire to the diaphragm.which
reproduces the voice.
Experiment has shown us that these desired results are realized by the
employment of two diaphragms within a single phone with a dividing space
between them, and filaments or other suitable connections extending from one to
the other and securely attached to both. The securing is the better obtained by
using a ring at the terminal of the filaments, and placing said ring against the
surface of the diaphragm the filaments passing through the diaphragm and being
utilized for retaining the ring in position by virtue of the tension of the filaments.
The diaphragms are arranged upon opposite sides of a globe or hollow casing and
by this means the vibrations of the contained air acting laterally on the connecting
filaments serve to materially emphasize the sounds transmitted, and thus increase
the power as well as the delicacy of the intrument.
We have employed with good results silken threads as the filamentary connections
between the diaphragms, the strength and accentuation of the sound being improved
by having a number of them. Our arrangement contémplates the use of a continuous
silk thread for all these interior_connections and it is threaded back and forth over

page_text: the rings at equal intervals its terminals being united to make it continuous. By
this arrangement all the connections exercise an equal strain upon the diaphragms,
and they may all be tightened simultaneously by taking up the thread at any
point. The rings are made preferably of metal, though they may be constructed
of any other suitable material. Braces also extend transversely across the rings on
the inner diaphragm and it is to these braces that the line wire is secured. Cords,
which may or may not be continuations of the connecting filaments before referred
to extend across the face of the outer diaphragm inwardly towards the ring, to
which they are attached. We have found by experiment that these cords intensify
and increase the volume of sound very much as well as strengthen the diaphragm.
The outer diaphragm is constructed of oiled parchment or sheepskin with one or
more layers of the same, and the supplementary diaphragm of silk or other textile
fabric may be arranged directly beneath or between them.
The inner diaphragm is made of linoleum.
The front of the telephone is provided with a cover which is supplemented either
by a speaking tube or trumpet or by a mouth piece and whistle.
Proceeding now to the next part of our invention it consists in means for
attaching and centering the telephone to the wall and also relates to a conduit for
the line wire to pass through.
At the rear of the phone is arranged a plate provided with a central opening.
Extending inwardly. from this opening is a pipe or conduit. This pipe may be
secured to the phone by screwing it into a plate set into the rear of the instrument.
It extends through the wall or partition and at the outer end is provided with a
centering device or an angle hanger secured to it; as by screwing. In the case of a
simple centering device we provide a shell, preferably of metal having openings at
suitable places through which we string a sliding cord. This device is automatic
or self centering. Or a piece of metal or parchment may extend from one edge of
the shell to the other. It is by one or the other of these devices that we centre
the line wire after it leaves the conduit. A combined centering device and angle
hanger may also be employed at this point.
A plate having an opening in it and a segmental arm radiating from one end, is
screwed into the pipe or conduit, and the line wire is strung through loops or rings
suspended from the angle hanger.
The simple angle hanger consists of a curved piece of metal or other suitable
material provided with openings through which a string is threaded. Small
metallic hooks are suspended in the loops of this string and in these hooks the line wire
is laid. Means of suspension and adjustment are also provided in connection with
the angle hanger. The object of this arrangement is to provide for the differentiation
in the tension of the line wire, which differentiation is caused from time to time
by the change in temperature or from other natural or artificial causes. The
construction of the angle hanger will pernit the line wire moving either in a
horizontal or vertical direction. As the object of the angle hanger besides
enabling the line wire gradually to change its position, is to prevent the molecular
action of the wire from being deranged or modified in the least, it is of primary
importance that the said wire should not at any one point be subjected to undue
pressure or tension, as the very objects of the hanger will be frustrated by the
abrupt change in the direction of the wire, which would be the natural sequence of
an extra tension at any one point. A uniform tension at all connecting points is
therefore a desideratum and is what we attain in our instrument.
A device for supporting and insulating the wire along the line of route is also
provided.
.
Referring to the drawings Figure 1 represents a side elevation partly in section
of the telephone, showing also the whistle and the mouth piece and also the conduit
and combined angle hanger and centering device attached.
Figure 2 is a plan view of the outer face of the outer diaphragm.
Figure 3 is a plan view of the inner, face of the inner diaphragm.
Figure 4 is a plan view of the telephone showing the hinged cap thrown back,

page_text: Figure 5 represents a phone, a conduit and a centering device, and Figure 6 a
supporting hook.
+
Figure 7 shows the continuation of the line wire extending over an angle hanger.
Figure 8 shows the phone in combination with the speaking tube, the pipe or
conduit and the angle hanger. Figure 9 is a plan view and Figure 10 an elevation
of the centering device.
In the drawings the phone proper is shown made up of parts A, A¹ and A¹¹.
The diaphragms B and B are attached to the outer edge of the central part A'
and over these are secured by suitable means the cover and back A and A¹¹. The
cap C is hinged to the cover A and to the aforesaid cap is attached the mouth
piece C¹ having hinged to it the metallic cap C₁ and reed or whistle D. The
rings E, E are arranged as shown in figures 1, 2 and 3 and they are connected
together by filaments F. These are strung over the rings shown in Figures 2 and 4.
F are cords which extend across the face of the diaphragm for holding the ring in
position and are not connected with the filaments F.
This arrangement augments the vibratory effects to a considerable extent. Upon
the back ring E¹ are placed metallic bridge pieces G and to these latter the line
wire H is attached.
It is composed preferably of two or three members as shown in Figure 1.
This construction of the line wire or cable has been found in practice to better
preserve the molecular action induced by the vibratory effects on the diaphragm.
Set into the rear of the phone is a circular metallic piece I, having attached to
it, as by means of a screw a pipe or conduit J. This latter extends through the
wall or partition W as shown in Figures 1 and 5. Attached to the outer end of
this conduit is either a self centering device K as shown in Figure 5 and in detail
in figures 9 and 10 or a combined centerer and angle hanger L as shown in
Figure 1. The centering device K consists of a shell having openings through which
a cord or cords may be strung and by means of these cords the line wire may be
centered. The preferred manner of effecting a centering of the wire at this point
is by means of small metallic strips K' which extend from one edge of the sbell
to the other. The line wire extends through a central opening in these strips.
When an angle hanger is employed at this point it is constructed in the manner
shown in figure 1 at L. A flat portion provided with an opening and an interior
threaded screw is attached to the conduit. It is provided with a segmental arm
extending from one end of the flat portion and from this arm are suspended loops
or rings L. The arm is shown in the drawings as curved but we contemplate
making it straight if so desired. Through these rings are extended the line wire.
At M is shown a suspending device or hook for ordinary usage along the line of
route. This device is represented in Figure 6.
In Figure 7 is shown an angle hanger. It consists of a semi-circular or curved
piece of metal or other suitable material N having openings through which is
strung a sliding cord N and in the loops of this cord are hung or suspended
small metallic books N'. The line wire rests and is supported in these latter. At O
in the same figure is shown an adjusting device for regulating the tension of the
line wire at this point.
In Figure 8 is a speaking tube arranged in connection with the phone where it
is desired to place the phone out of the way, as happens in some instances. This
tube is also provided with the mouth piece C'.
Though we have described this instrument more particularly as a transmitting
telephone, it is to be understood that it is equally as well adapted for a receiving
or reproducing device without any modification whatsoever. Persons using the
instruments can listen and respond equally well through the same phone.
The arrangements and parts we have shown and described constitute a system
of telephony which will fulfil all the conditions requisite for establishing a
thorough and efficient means of communication within certain described limits
and we contemplate its introduction and usage in dwellings, manufactories,
warehouses and also between several neighbouring places.

page_text: 'Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
☐ 1. A complete system of acoustic or mechanical telephony substantially as
herein before described.
!
2. In a system of acoustic or mechanical telephony a transmitting device, a
conduit, centering device, angle hanger, line wire, and receiving or reproducing
instrument substantially as herein before described.
3. In an acoustic or mechanical telephone à transmitting instrument having two
diaphragms the outer being made of one or more thicknesses of parchment and
the inner one being made of linoleuin.
4. In an acoustic or mechanical telephone the combination of the two diaphragms
the rings situated as shown in figures 1, 2 and 3 and the connecting filaments.
5. In an acoustic or mechanical telephone the combination of the inner and
outer diaphragms, the rings, the connecting filaments, the metallic bridges on the
inner ring and the line wire, as set forth and shown.
6. In an acoustic or mechanical telephone, the combination of the transmitting
instrument substantially as hereinbefore described, with the pipe affording a
conduit for the line wire.
7. In an acoustic or mechanical telephone, the combination of the transmitting
or receiving instrument, the line wire, the conduit and the self centering device
as shown and described.
8. In an acoustic or mechanical telephone the combination of the transmitting
or receiving instrument, the line wire, the conduit and the combined angle hanger
and centering device as shown in figure 1.
9. In combination with our system of acoustic or mechanical telephony the
angle hanger shown in figure 7 or its substantial equivalent.
10. In combination with our system of acoustic or mechanical telephony a reed
or whistle and mouth or ear piece as shown in figures 1, 4, and 5 or a speaking
tube as shown in figure 8.
11. In combination with our system of acoustic or mechanical telephony, an
angle hanger supporting the line wire and provided with a device for adjusting
the tension of the same, as shown at O, in figure 7.
17:1 1002