Year: 1886

page_text: I EDWIN POWLEY ALEXANDER of 36 Southampton Buildings in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature
of this invention (communicated to me from abroad by Hugh Lamont of Blissfield
in the County of Lenawa State of Michigan, United States of America) to be as
follows:-
Heretofore the central idea in mechanical telephones was that of a thin disc or
diaphragm in tense relation to the line-wire stretching therefrom; the delicacy in
structure of the disc being regarded as an essential to its responsiveness.
Now this invention differs essentially in principle from such prior devices and
consists in certain improvements in the construction of mechanical telephones
whereby the need of the usual diaphragm is dispensed with; the molecular
vibrations being imparted to the line wire and being received therefrom without
the necessary interposition of any delicate plate or disc, capable of sensible
oscillation, and such as is ordinarily understood to be requisite in devices of this
character.
In my improved Mechanical Telephones an anchor-support or bar which may be
of wood metal or other material, the molecules of which are capable of being
maintained in tense or sensitive condition by subjecting the bar to strain is
securely fastened to the wall of the room or other convenient point-The said bar
is preferably made of steel tapering slightly from its base-fastenings to the free
terminal and curved or somewhat bowed in contour. A sheet of rubber felt or the
like may be interposed between the base of the bar and the wall to prevent the
ingress or egress of vibrations at such point to or from the bar. Near the upper
end of this vibrant bar the line wire is secured in any convenient manner extending
thence to the next station as usual. When the line wire is stretched tightly in
position the stress comes directly upon the bar which constitutes a species of blade
spring and which is thereupon so far modified in condition as to develope in all
parts thereof, except its fixed base, a highly sensitive or tremulous state of its
particles.

page_text: In such state the bar becomes a veritable microphone, susceptible to the slightest
tremors which may be imparted thereto and repeating these with marked fidelity
to its proper connections. This vibrant peculiarity of the bar is utilised in lieu of
the oscillation of the thin diaphragm of the ordinary telephone in receiving and
transmitting articulate speech. The vibrant bar terminates in something of a
point at its free end upon which point may be loosely mounted an ordinary
telephone box which may consist of the two usual rigid sections or parts between
which is clamped a disc of wood paper-pulp or the like; said disc having a thimble
or eyelet set in its central orifice to receive the end of the vibrant bar. The box
can turn freely about its support or be permanently fastened thereto, and with its
diaphragm performs no necessary function other than .to direct and concentrate
upon the sensitive vibrant bar the impulses due to the sound waves. The tremors
thus imparted to the bar pass to the line-wire and so to the station in communi-,
cation therewith. In conjunction with the. vibrant bar to which the line wire is
secured there is provided a vibrant receiver which may be of similar material to
the said bar, and which is preferably bent in a U or bow-like form so that the
ends thereof can bear with slight elasticity against the ears of the operator
when the receiver is distended and applied. Plates or spherical knobs of india-
rubber, metal, gutta-percha, or the like may be attached to the ends of the
receiver for comfort and ease in resting the same against the ears. Being thus in
readiness the operator needs but to touch the vibrant receiver against some point
of the vibrant bar preferably short of its fixed base whereupon the impulses
imparted to said bar from the line, are at once communicated with exceeding
clearness and fidelity along the sensitive receiver to the ear. For convenience
there may be a hole in the receiver by which whilst messages are passing the
latter may be fitted over and sustained upon the pointed end of the vibrant bar
although as above stated any other point along the bar will serve for the
escape of the molecular tremors to the vibrant receiver. If desired the
vibrant receiver may be dispensed with entirely and the point of the vibrant
bar be held between the teeth, the impulses being communicated thence directly
by the teeth and roof of the mouth to the ear and auditory nerve.
Or again
instead of bringing the receiver directly in contact with the vibrant bar a
.suspension-cord connected to the vibrant bar (especially if such cord be of
piano wire or the like), may be drawn taut and thus serve as a medium for
communicating the impulses from the bar to the receiver. In practice it has been
found that for short distances the disc of the telephone box although but loosely
set upon the point of the vibrant bar serves as a receiver and will distinctly
reproduce the sound waves. Over longer lines however, or where many abrupt
angles occur the vibrant receiver will better perform the desired function.. If
desired an ordinary speaking tube may be attached to the free end of the vibrant
bar in substitution for the telephone box and its diaphragm, a plug of coŕk, rubber
or the like in the speaking tube, furnishing a convenient means for affixing said
tube to the bar although the same is not essential. The vibrant receiver may be
used by the operator as before described or the speaking tube itself may serve
directly as the medium for transmittal both from and to the vibrant bar. When
so employed it is convenient to branch the tube after it leaves its attachment with
the vibrant-bar; one of said branches passing to the mouth and the other to the
ear of the operator. In this particular construction, having the speaking-tube as
part thereof the plug performs in molecular transmittal the same function as does
the diaphragm of the previous form.
According to another modification the vibrant-bar from which the line wire
leads, instead of being fixed at one end as first described is set pivotally upon a
rod said rod being sustained by posts or uprights mounted preferably in sockets
of rubber in a base-board. The line-wire passes from the vibrant-bar and is con-
veniently fastened to an adjusting device by which it can be drawn tight to secure
the requisite tension. When thus adjusted the, the tension is immediately reflected
upon the bar which thereupon becomes highly sensitised as before and tremulously

page_text: .
susceptible to the passing impulses. The flat diaphragm of the ordinary telephone
may be applied if desired to any part of the vibrant bar and thus serve to receive
or transmit the impulses. Obviously, however there is no tension upon the
diaphragm of the telephone. If desired the vibrant receiver may be used in con-
junction with the diaphragm transmitter, and upon being brought in contact with
the vibrant-bar serves to convey the passing impulses to the ear of the operator as
already detailed. In some cases the line-wire instead of proceeding directly from
the vibrant-bar is in connection with the diaphragm or disc of the telephone as in
usual practice. The bar in this form is attached at its forked or branching ends to
the two sides of the telephone box; but in such relation said bar is far more than
a mere bracket-support to the telephone box; for when the line-wire is tightly
stretched as is necessary the vibrant qualities of the bar are at once developed, and
the sensitiveness of the telephone is thereby greatly increased. The vibrant,
receiver can be applied to the bar in this form of mechanism, and the tremulous
impulses existing therein be transmitted by means of said receiver to the ear as:
before. This, vibrant peculiarity of the bar enables a much stronger and stouter
diaphragm to be used than is ordinarily admissible so that the tension or pull of
the line-wire can in consequence be better resisted. The telephone box and the
diaphragm itself in the form now under consideration become in effect no more
than an expanded continuation of the vibrant-bar proper, and in such view
transmit the wave impulses, not by sensible oscillation but by internal molecular
impact. In any modification in form of which this invention is susceptible, this
expedient of a vibrant bar situate at the terminals of the line-wire and highly
responsive to the molecular disturbances imparted thereto is to be observed. So
sensitive does the vibrant bar become under tension, that in many instances it is
quite capable of acting directly to, transmit the impulses of the line, without the
interposition of the telephone diaphragm at all. The use of such diaphragm
however is in general desirable, although the construction thereof and the point of
its connection with or application to the vibrant bar are comparatively unimportant.
Excellent results are obtained by employing wood, or paper pulp sheets as the
material for the diaphragm as herein before specified. It will be understood that
whilst the best effects are obtainable when the vibrant-bar extends from its base
support outward and is free to the terminal point thereof such peculiar shape is not
essential nor is it necessary that the bar should remain unsustained except at its
base fastenings. Wedge blocks inserted at the back of the bar above its base and
between the bar, and the wall do not destroy the sensitiveness of the mechanism.
If there be any portion thereof under tension from the line-wire, causing the
molecules to be thrown into a condition of strain or unstable equilibrium the bar
will act with more or less success to transmit the impulses.
Dated this 16th day of Ansil 1996

page_text: I EDWIN POWLEY ALEXANDER of 36 Southampton Buildings in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature
of this invention (communicated to me from abroad by Hugh Lamont of Blissfield
in the County of Lenawa State of Michigan, United States of America) and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
Mechanical telephones of ordinary construction are provided with a thin disc of
metal parchment or the like commonly known as the diaphragm which is mounted
in position across the mouth of the telephone box and has the line wire attached
thereto. If words are spoken in near proximity to the telephone diaphragm this
latter being light and delicate in structure is sensibly affected. The air waves
tend to develope oscillations corresponding therewith in the light diaphragın which
movements are transmitted thence to the line wire and so to the telephone at the
communicating station. At such point the companion diaphragm is caused to
oscillate in keeping with the impulses received through the line wire thereby
throwing the adjacent air into waves of similar character which are impressed
upon the ear of the person at the receiving instrument-Unless the diaphragın is
thin and delicate it is incapable of any freedom of oscillation and cannot perform
the necessary function of receiving from and imparting to the air the wave
movements distinctive of articulate speech-The motion of the diaphragın is
essentially that of actual sensible oscillation and not merely of internal molecular
vibration of impact like that which occurs throughout the line wire. Aside from
having a light delicate diaphragm it is essential in telephones of this class that
sensitive tension be maintained between the diaphragm and the line wire. If the
connection between these parts be entirely broken no transmission of the impulses
from one to the other can occur-And in corresponding degree so far as approach
is made to this condition of complete isolation by permitting the connection
between the line wire and diaphragm to become loose and slack so far is the
sensitiveness of the instrument impaired; it becomes more and more incapable of
transmitting the finer shades of impulse.upon which clearness and distinctness
of articulation depend. In practice provision is invariably made for securing this
necessary taütness of adjustment between the line wire and the diaphragm and in
some instances compensating devices have been proposed the object of which is to
effect such adjustment automatically. These automatic devices consist of an
ordinary coil-spring set loosely between the telephone box and its base support
so that in such relation of the parts the box and diaphragm may shift and
accomodate themselves to the changes in length of the line wire (arising from
variations in temperature) to which the wire is subjected. Over wires of any
considerable length the extremes of expansion and contraction must work with
destructive effect upon the diaphragms of the telephone boxes connected therewith
when these latter are provided with compensating springs as above mentioned
If the compensating spring be powerful enough to adjust the telephone box and
diaphragm to any expansion of the line wire that may occur the spring .is quite
as powerful in resisting the contraction of the wire-But such resistance manifestly
reacts upon the delicate diaphragm during any extreme contraction of the wire
and causes the diaphragm to be torn or broken from its line connection. If the

page_text: spring be diminished in power to avoid this difficulty it no longer serves to com-
pensate for the extreme expansion of the line so that at times the connection of the
latter with the diaphragm is slackened and the efficient transmission of the impulses
no longer occurs-Even though no compensating spring be employed the stress of
the line wire frequently serves to tear the diaphragm from its connection. Hereto-
fore the central idea in mechanical telephones was that of a thin disc or diaphragm
in tense relation to the line wire stretching therefrom, the delicacy in structure of
the disc being regarded as an essential to its responsiveness Now this invention
differs essentially in principal from such prior devices and consists in certain
improvements in the construction of mechanical telephones whereby the need of
the usual diaphragm is dispensed with the molecular vibrations being imparted
to the line wire and being received therefrom without the necessary interposition
of any delicate plate or disc capable of sensible oscillation and such as is ordinarily
understood to be requisite in devices of this character.
Fig. 1 is a sectional view of one form of my improved telephone with the vibrant
receiver secured thereto. Fig. 2 a front elevation of the transmitter and vibrant
bar in position. Fig. 3 a detail view shewing the telephone in modified form-
Fig. 4 a view in perspective shewing a different mode of securing the line wire to
the vibrant bar. Fig. 5 is a view in section illustrating the plan of attaching the
vibrant bar to the telephone box.
Securely fastened to the wall A of the room or other convenient point is the
anchor support or bar B which may be of wood metal or other material the
molecules of which are capable of being maintained in tense or sensitive condition
by subjecting the bar to strain. The bar is preferably made of steel tapering
slightly from its base fastenings b to the free terminal and somewhat bowed in
contour as shewn. A sheet of rubber felt or the like as at 61 may be interposed
between the base of the bar and the wall to prevent the ingress or egress of
vibrations at such point to or from the bar. Near the upper end of the bar B the
line wire C is secured in any convenient manner extending thence to the next
station as usual. When the line wire is stretched tightly in position the stress
comes directly upon the bar or spring B which thereupon is so far modified in
condition as to develope in all parts thereof except its fixed base a highly sensitive
or tremulous state of its particles. In such state the bar becomes a veritable
microphone susceptible to the slightest tremors, which may be imparted thereto.
and repeating these with marked fidelity to its proper connections. This vibrant
peculiarity of the bar is utilized in lieu of the oscillation of the thin diaphragm
of the ordinary telephone in receiving and transmitting articulate speech. The
bar B terminates in something of a point b' at its free end upon which point may
be loosely mounted an ordinary telephone box as at D. The box D may consist
of the two usual sections d d between which is clamped a disc d³ of wood paper
pulp or the like said disc having a thimble or eyelet d³ set in its central orifice to
receive the end of the vibrant bar B. The box D can turn freely about its support
or be permanently fastened thereto and with its diaphragm performs no necessary
function other than to direct and concentrate upon the sensitive vibrant bar the
impulses due to the sound waves. The tremors thus imparted to the bar pass to
the line wire and so to the station in communication therewith. In conjunction
with the vibrant bar B to which the line wire is secured there is provided a vibrant
receiver E which may be of similar material to the said bar and which is preferably
bent in a U or bow like form so that the ends thereof can bear with slight elasticity.
against the ears of the operator when the receiver is distended and applied. Plates
or spherical knobs e of india rubber metal gutta percha or the like may be attached
as shewn to the ends of the receiver for comfort and ease in resting the same
against the ears. Being thus in readiness the operator needs but to touch the
vibrant receiver against some point of the vibrant bar B preferably short of its
fixed base whereupon the impulses imparted to said bar from the line are at once
communicated with exceeding clearness and fidelity along the sensitive receiver_to
the ear.
For convenience there. may be a hole-as at ein the receiver by, which

page_text: whilst messages are passing the latter may be fitted over and sustained upon the
point b of the vibrant bar B although as above stated, any other point along
the bar B will serve for the escape of the molecular tremors to the vibrant
receiver. If desired the vibrant receiver may be dispensed with entirely and the
point of the bar B be held between the teeth the impulses being communicated
thence directly by the teeth and roof of the mouth to the ear and auditory nerve.
Or again instead of bringing the receiver directly in contact with the vibrant bar
the suspension cord e¹ (especially if it be of piano wire or the like) may be drawn
taut and thus serve as a medium for communicating the impulses from the bar to
the receiver.
In practice it has been found that for short distances the disc d of the telephone
box D although but loosely set upon the point of the vibrant bar B serves as a
receiver and will distinctly-reproduce the sound waves. Over longer lines however
or where many abrupt angles occur the vibrant receiver E will better perform the
desired function-As illustrated in fig. 3 an ordinary speaking tube F may be
attached to the vibrant bar B in lieu of the telephone box.and its diaphragm as in
figs. 1 and 2; a plug f of cork rubber or the like in the speaking tube furnishing a
convenient means for affixing said tube to the bar although the same is not
essential. The vibrant receiver E may be used by the operator as before described
or the speaking tube itself may serve directly as the medium for transmitting both
from and to the vibrant bar. When so employed it is convenient to branch the
tube after it leaves its attachment with the vibrant bar, one of said branches
passing to the mouth and the other to the ear of the operator. In this particular
construction having the speaking tube as part. thereof the plug f performs in
molecular transmittal the same function as does the diaphragın d² of the previous
form. In fig. 4 the vibrant bar B' from which the line wire A¹ leads instead of
being fixed at one end as first described is set pivotally upon the rod g, said rod
being sustained by the posts h mounted preferably in sockets of rubber as at i in
the base board I. The line wire A¹ passes from the bar B¹ and is conveniently
. fastened to the adjusting device K by which it can be drawn tight to secure the
requisite tension-When thus adjusted the tension is immediately reflected upon
the bar B¹ which thereupon becomes highly sensitized as before and tremulously
susceptible to the passing impulses. The flat diaphragm of the ordinary telephone
may be applied as shewn in dotted lines to any part of the vibrant bar B¹ and thus
serve to receive or transmit the impulses-Obviously however there is no tension
upon the diaphragm of the telephone. If desired the vibrant receiver E may be
used in conjunction with the diaphragm transmitter and upon being brought in
contact with the bar B¹ serves to convey the passing impulses to the ear of the
operator as already detailed. As shewn in fig. 5 the line wire instead of proceeding
directly from the vibrant bar B is in connection with the diaphragm or disc of the
telephone as is the usual practice. The bar B in this form is attached at its forked
or branching ends to the two sides of the telephone box, but in such relation said
bar is far more than a mere bracket support to the telephone box, for when the line
wire is tightly stretched as is necessary the vibrant qualities of the bar B are at
once developed and the sensitiveness of the telephone thereby greatly increased.
The vibrant receiver E can be applied to the bar in this form of mechanism and
the tremulous impulses existing therein be transmitted by means of said receiver to
the ear as before. This vibrant peculiarity of the bar B enables a much stouter
and stronger diaphragm to be used than is ordinarily admissible so that the tension
or pull of the line wire can in consequence be better resisted. The telephone box
and the diaphragm itself in the form now under consideration become in effect no
more than an expanded continuation of the vibrant bar proper and in such view
transmit the wave impulses not by sensible oscillation but by internal molecular.
impact. In any modification in form of which my invention is susceptible this
expedient of a vibrant bar situate at the terminals of the line wire and highly.
responsive to the molecular disturbances imparted thereto is to be observed. So
sensitive does the vibrant bar become under tension that in many instances it is
a

page_text: quite capable of acting directly to transmit the impulses of the line without the
interposition of the telephone diaphragm at all. The use of such diaphragm however
is in general desirable although the construction thereof and the point of its connec-
tion with or application to the vibrant bar are comparatively unimportant. Excellent
results are obtained by employing wood or paper pulp sheets as the material for the
diaphragm as hereinbefore described.
In the practice of this invention it is obvious that many minor changes may be
made. not affecting the principles thereof-Since the stress of the line wire comes
ordinarily upon the vibrant bar direct it is obvious that the stout bar will allow
heavier wires or even cables and a higher tension of the line to be employed than
the delicate diaphragms of the old style of mechanical telephones could permit.
Changes in tension of the wire which would throw the ordinary diaphragm
completely out of service may occur in the new form without materially affecting
the sensitiveness of the line. It will be understood that whilst the best effects are
obtainable when the vibrant bar extends from its base support outward and is free
to the terminal point thereof such peculiar shape is not essential nor is it necessary
that the bar should remain unsustained except at its base fastenings. Wedge blocks
inserted at the back of the bar above its base and between the bar and the wall do
not destroy the sensitiveness of the mechanism. If there be any portion thereof
under tension from the line wire causing the molecules to be thrown into a condition
of strain or unstable equilibrium the bar will act with more or less success to transmit
the impulses.
•
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. In mechanical telephones the combination with the line wire of the vibrant
bar in tense connection therewith said bar serving to receive and transmit the
molecular impulses from and to the line wire substantially as described.
2. In mechanical telephones the combination with the line wire of the vibrant
bar in tense connection there with and the sound transmitter mounted upon said
bar substantially as described.
3. In mechanical telephones the combination with the line wire and with the
vibrant bar in tense connection therewith of the vibrant receiver for said bar the
same being capable of application to the ear of the operator substantially as
described.
4. In mechanical telephones the combination with the line wire and with the
vibrant bar in tense connection therewith of the elastic vibrant receiver for said bar
the same being capable of application to the ear of the operator substantially as
described.
5. In mechanical telephones the combination with the line wires of the vibrant
bar in tense connection therewith and the telephone box the diaphragm of which
bears freely upon said bar substantially as described.
6. In mechanical telephones the combination with the line wire of the vibrant
bar in tense connection therewith and the telephone box the diaphragm of which is
loosely and pivotally set upon said bar substantially as described.
7. In mechanical telephones a vibrant receiver adapted to conduct the molecular
vibrations from the vibrant bar to the ear of the operator substantially as described.
8. In mechanical telephones the combination with the line wire of the vibrant
bar in tense connection therewith and the telephone box having paper pulp
diaphragm to bear against said bar substantially as described.
Dated this 5th day of November 1886.
EDWIN P. ALEXANDER,