Improvements in Sound-locating Instruments.
Year: 1897

page_text: Date of Application, 14th Sept., 1897-Accepted 30th Oct., 1897
COMPLETE SPECIFICATION.
[Communicated from abroad by DAVID PORTER HEAP, Engineer, of Tompkinsville,
Staten Island, State of New York, United States of America.]
Improvements in Sound-locating Instruments.
I HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, 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:-
This invention relates to improvements in what are known as sound-locating
instruments, the principal purpose of which is to enable vessels to change their
direction of movement with relation to dangerous objects, such as other vessels,
icebergs, the shore, or similar obstacles to their safe movement, and thus avoid
contact or collision with them. This purpose is attained by means of such an
instrument as above referred to, whereby the direction or source of sounds produced
at, or reflected from, a more or less distant point from the instrument, may be
determined in time to enable the vessel to escape, if necessary, any danger the
source of sound may offer. The usefulness of this instrument is especially realized
by its employment as an aid to navigation, when the sound-producing object, say,
another vessel, may not be visually perceived, as at night, during foggy weather,
or by reason of distance; but the instrument is susceptible of other uses, as during
a war, when it is desirable to ascertain the location of an approaching body of
men, or the position of a dangerous cannon and the like, when the same are not
visible.
The present invention consists in novel constructions of the instrument (fully
hereinafter explained and claimed), the object being not only the increase of
sensitiveness of these instruments, whereby the range of sound-detecting capacity.
is enlarged, but also to improve the mode of operation, whereby exactitude in
determining the direction of the sound is attained, without extensive movement
of the instrument, so that a sound produced by any means, such as by a horn,
bell, whistle, or cannon, or a sound deflected from any object, as by echo, or one
made as by a body of men, may be detected, and its direction indicated acoustically.
By this means, the direction of movement of a vessel may be changed,
and a safe course be made, while the vessel carrying the sound pro-
ducing instrument is at a sufficient distance, and thus avoid collision
with said vessels or object, or some other advantage be taken of the
definite knowledge thus attained, such as the making or facilitating of an attack
on a body of troops, or its armament, or distant sound signals be effectively heard
and understood.
Practical embodiments of these improvements, which constitute an instrument
to which the name "Topophone" has been given, are illustrated in the accom-
panying drawings, in which:
-
Fig. 1 is a rear elevation of the instrument provided with a supporting standard,
hold or maninulated by the onerator.

page_text: Fig. 2 is a plan view of the instrument, the dotted lines being added to indicate
the direction of sound waves.
Fig. 3 is an enlarged vertical sectional elevation of the same, as viewed from
the rear.
Fig. 4 is a side elevation of the same, as seen looking in the direction of the
arrows in Figs. 1 and 3.
Fig. 5 is a side elevation of an instrument in which the receivers are supported
a distance apart, and are without a front guard.
Fig. 6 is a side elevation of another form and arrangement of receivers, in
which this invention may be embodied.
Fig. 7 is a plan view thereof; and
Fig. 8 is a plan view of still another form and arrangement of receivers, in
which, the invention may be embodied..
The essential characteristic features of this instrument are two acoustic receivers,
whose mouths point in substantially opposite directions, and thus made incapable
of simultaneously pointing in the same direction, or in that of the object producing
the sound, the location of which it is required to determine, said receivers being
provided with sound conductors for conveying the sound to the ears of the.user;
all of which is hereinafter fully explained and claimed..
In the precise embodiments shown in the drawings of the present invention,
which are preferable forms, the example shown in Figs. 1 to 4 comprises sound
receivers B, C, which are in general structure of conical form, their diminishing
stems or rearward portions being curved at approximately right angles to their
mouth portions, so that the receivers may preferably be supported above the head
of the user, and normally stand with their mouths pointing in substantially
diametrically opposite directions, and at right angles to the line of vision of the
user, to whose cars said diminishing, stems or rearward terminations are directly
connected by conducting tubes 22, 23, and suitable ear pieces, the parts being
supported by suitable mountings, whereby the instrument may be conveniently
turned in respect to the source of sound.
These sound receivers are separate and distinct members secured together in
their described relation (in this one of the preferable forms) by being fastened with
stay bands. 40, 50, which attach them to the head H of a carrying staff, as S. This
staff may be operated wholly by hand, or be supported on sonie base, and vibrated
by some attachment.
Although not requisite to the proper operation of this instrument, for the reason
their described relation (in this one of the preferable forms) by being fastened with
appears by another illustration, it is desirable to provide them with a guard or
deflector D, which, at times, so protects them that the sound waves may be
wholly or partially excluded from both or either of them. In Figs. 1 to 4, the
guard is shown as arranged in front of, and close to, their outer sides, so as to at
feast cover the same, although it is preferable that this guard or deflector D shall
extend somewhat beyond the mouths or open ends of the sound receivers.
This guard, which is similar to, and serves a similar purpose to, the front guard
described in British Patent No. 17591 of 1895, is shown as slightly curved, and
this is desirable, as that form tends to deflect the sound waves which are to be
rejected from action therewith, away from the instrument, but said deflecting
guard may be straight. Any mode of attaching the guard to the receivers may
be adopted, as the angle bars 2, 3.
.
Although the receivers are shown as supported for use by a staff, as S, and
notwithstanding that it is preferable to support them above the head of the user,
this instrument, may be mounted for use in various ways. Thus, it might be
supported on a tripod or other stand, so as to be capable of moving pivotally
thereon, its sound conductors B, C, being continued to ear pieces by suitable
connections, as the tubes 22, 23, but other modes of supporting the said receivers,
so that they may be connected respectively with the right and left ears of the

page_text: operator, and yet be readily moved with respect to the direction of the sound, by
which the advantages of this invention may be attained, will be apparent.
This instrument may be embodied, as in Figs. 5 to 8, wherein structures are
shown which are devoid of any front guard. Such guard may be omitted for the
reason that, in some structures of this instrument, its sides themselves act as a
guard, as is especially apparent from Fig. 6, but for some uses the structure of
Fig. 5 is perfectly available, for the reason that, with the other protections
against the injurious action of sound waves pässing the instrument, or otherwise
reaching the operator, as hereinafter explained, the instrument is operative for
many, if not all, of the uses for which it is designed, whether or not it is provided
with the enlarged rim, M..
In the modifications containing the invention shown in Figs. 6, 7, and 8, the
sound receivers are somewhat different, in form and relative arrangement from
those in Figs. 1 to 5, but point in substantially opposite directions.
In the special use of this instrument, as upon vessels, or in similar situations,
whether or not the operator is housed, it is important to protect the ears from
extraneous or local sounds, by covering the head of the operator with a non-
conducting helmet, so that such sounds may not be heard through impact with
the body, or portions thereof.
A good form of helmet and car piece.carrier is illustrated and described in said
prior patent, and it should be stated that such a helmet may be extended to cover
the face of the user to a greater extent than is shown in such patent, and be
extended downward by a sound-proof appendage, that will more or less protect the
body of the user from conveying sound to his ears. Of course, the means for
protecting the body from conducting sounds to the ears may, instead of being
connected with the helmet, be a separate structure fastened thereon, or be inde-
pendent of the helmet, and, when adjusted, to co-operate therewith, so as to protect
as much of the person of the operator as may be found desirable.
As isolation of the instrument from the conduction of sound waves other than
those which enter the mouths of the acoustic receivers, is essential to perfect
results, especially when the sound-producing object is very distant, or the sound is
weak, it is important that the instrument itself shall be adequately protected
from transmitting local sounds, as well as those it is desired to locate, and this is
partially realized by the non-conducting feature of the instrument described in
said prior patent. It has been found, however, in practical use, that no matter
what material composes the acoustic receivers themselves, they must, in order to
attain the highest efficiency, be made sound-proof by incorporating with them
some means rendering them sound-proof; or, in other words, rendered incapable
of transmitting, through their walls, sound waves impinging upon their exterior
surfaces or sides. This is accomplished by making them out of non-sound-con-
ducting substance, as wood fibre, which may, if made thick enough, be capable of
self support, though it is preferable to provide it with a metal portion to aid its
support. Another way to effect the same result, is to construct the receivers with
double walls, so as to provide a space between them, and to interpose between the
composite wall of each, some non-sound conducting material, as is shewn in
Fig. 3, where the space thus provided between their double walls is filled, packed
with, or contains, a non-sound-conducting material.
The use of this instrument will be explained with special reference to Figs. 1
to 4. It is obvious that when the same is presented with the sides of its acoustic
receivers facing or directed to the source of sound, as shewn in full lines in Fig. 2,
whether or not it has the front guard D, the waves of sound represented by the
parallel dotted lines in said figure, will impinge against such sides, or move past
their open mouths, without entering therein. If, under this adjustment or
presentation of the instrument, it should be presented not directly toward the
source of sound, as is indicated by the dotted outlines of it in said Fig. 2, some
of the waves of sound will then enter from the left-hand side of the observer, and

page_text: be directed into the left-hand receiver, at which time the waves of sound on his
right-hand side will pass beyond the right-hand receiver without entering it.
Thus the sound waves entering the left-hand receiver will be heard in his left ear,
and none will be practically audible in his right ear, and hence he will know
positively that the source of sound is upon his left hand side, and if he then turns
the instrument to the left, until he hears the sound in his right ear, he will have
found limits of direction within which that sound-producing object must exist,
and will then be able to tell the general direction of such sound. If, now, upon
vibrating the instrument to the right hand, until the sound is again heard in the
right ear, the observer will know that a horizontal line at right angles to the axis
of the two receivers has passed the line of direction of the sound, and if he then
vibrates the receivers so as to hear the sound alternately in each ear, he will have
reduced said limits, and know that a line bisecting the angle of oscillation will
be the line of direction of the sound.
It will thus appear that the range f vibration necessary to locate the sound by
the use of this peculiar instrument, is diminished to a small degree, thereby
enabling a speedy location of the direction of sound to be found, with but slight
movement of the instrument itself.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to me
from abroad, I declare that what I claim is:-
1. A sound-locating instrument consisting of two acoustic receivers whose
mouths point in substantially opposite directions, said receivers having their
inner ends provided with sound conducting tubes having means for connecting
each with an ear of the observer, substantially as described.
2. A sound-locating instrument consisting of two acoustic receivers whose
mouths point in substantially opposite directions, and whose inner ends are
provided with sound-conducting tubes having means for connecting each with
an ear of the observer, said receivers being provided with a sound-obstructing
guard, substantially as described.
A sound-locating instrument consisting of two acoustic receivers whose
mouths point in substantially opposite directions, each composed of non-sound-
conducting walls, substantially as described.
D
1
NEWTON & SON,
Agents for the Applicant.