Improvements in Sound-receiving Apparatus.
Year: 1890

page_text: Date of Application, 19th Mar., 1890-Accepted, 3rd May, 1890
COMPLETE SPECIFICATION.
Improvements in Sound-receiving Apparatus.
I FRANK DELLA TORRE, of Baltimore, in the County of Baltimore, State of Mary-
land, United States of America, gentleman, do hereby declare the nature of my
invention for IMPROVEMENTS IN EOPHONES, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My present invention relates to a new and improved apparatus for detecting and
determining the direction or position of an object from which sounds eminate or are
reflected and is especially designed for use as an aid to navigation or for ascer-
taining the position of a more or less distant object at night, during foggy weather or
under similar conditions precluding visual observations.
As is well known the navigation of vessels at night, and during foggy weather, is
attended with great danger owing to the extreme difficulty if not impossibility of
locating or determining the position of objects such as vessels, icebergs, the shore
and other obstacles.
In such cases recourse is had to acoustic signals such as fog horns, bells, whistles
etc., for indicating the presence of danger, such signals being either originated at the
distant station or transmitted therefrom by reflection.
Experience has demonstrated the unreliability of ordinary acoustic signals, under
such circumstances, as a means for accurately determining the position of the vessel
or other object from which the signal is sent, for, while the general direction of the
place from whence the sound proceeded may at times be fixed, the margin of error
is so great as to render the information thus derived unreliable and insufficient.
My present invention has for its object to provide means whereby an observer can
quickly and with great accuracy determine the direction of the object or station from
whence the acoustic signals are transmitted, and is thus enabled to locate the obstruction
or other object.
The principal elements of such an apparatus are two sound receivers or collecting
devices isolated the one from the other by a vertical position or vane extending
horizontally between said receivers, the whole mounted to turn about a vertical
axis, together with means for separately conveying the sounds operating upon or
through each receiver to the observer.
Generally speaking these devices are arranged for operation as follows: The
partition or vane serves both as a reflector and a protection for the two receivers,
that is to say, a receiver is located in proximity to each face or reflecting surface
of the partition and in such relation thereto that sound waves striking the face of
the partition at an angle to the plane thereof will be directed into or against the
receiver appropriated to that side, while the receiver appropriated to the other or
opposite side of the partition will be protected by the latter and the sound waves
operating on the one side will thus be prevented from entering or acting upon said
receiver on the opposite side, it being for the time, in the acoustic shadow.
In order that the observer may readily determine which receiver is at any given
time within the range of the signal and which in shadow, the receivers are provided
with separate conveyors through which the sounds acting thereon are transmitted
to the observer.
The reflecting surfaces of the partition or vane are arranged in substantially parallel
planes so that when the longitudinal axis of the vane or partition is brought parallel
with a line drawn from the transmitting to the receiving station, the receivers on
opposite sides will be equally exposed to the direct action of the sound waves, but
when the apparatus is turned about its vertical axis only one receiver and reflecting

page_text: surface will be exposed, the other being in the acoustic shadow of the sounds impinging
upon the surface facing the transmitting station.
By furnishing each receiver with a separate sound conveyor, the observer is enabled
to at once, and with certainty, ascertain which reflecting surface is for the time
eing exposed to the direct action of the sound waves proceeding from the transmitting
station, thereby determining the direction of the transmitting station to be on that
side of the longitudinal axis of the partition on which the responsive receiver is
located.
Having ascertained this fact he moves the apparatus about its vertical axis until
the opposite receiver is made responsive to the sound waves, thereby locating the
transmitting station at a point intermediate the two positions from which observation
had been taken. By moving the apparatus back and forth and carefully noting
the alternate response of the two receivers the observer is enabled to quickly
adjust the apparatus so that the response or sounds transmitted from both receivers
will be equal and when this point has been ascertained and determined it will be
found that the longitudinal axis of the partition or vane will stand on the line
drawn from the transmitting to the receiving station, thus fixing the direction or
position of the transmitting station and enabling the navigator to approach or
avoid it as may be desired.
The invention also comprehends, in addition to the general features bereinbefore
outlined, certain novel details of construction tending to improve and enlarge the
capacity of the apparatus, all as hereinafter more fully described.
In the accompanying drawings:-
Figure 1 is a side elevation of the apparatus.
Figure 2 is a perspective view of the partition or reflector and receiver.
Figure 3 is an end view partly in section.
Figure 4 a detail sectional view.
Similar letters of reference in the several figures indicate the same parts.
The portion of the apparatus hereinbefore referred to as a partition or vane is desig-
nated A, and the receivers, B, B, the whole mounted upon a shaft serving as the
vertical axis, about which they are moved for adjustment.
The partition A is preferably constructed in the form shown, and comprises a
head or block horizontally disposed and having its opposito parallel surfaces concaved
vertically to increase the reflecting power. This concave form of the reflecting surfaces
is more especially valuable when the apparatus is designed for use on vessels and is
subjected to the rolling action of the boat.
The partition may be made solid or in sections, but is preferably formed of a
hollow metallic case a filled with or surrounding a light central core a' and is
secured at the center of its length to the vertical shaft C, so that it will present
about the same surface to the wind on opposite sides of the axis and thus be in
balance, thereby rendering it capable of being easily revolved about its axis.
On each side, and in close proximity to the reflecting surfaces of the partition, one
of the receivers B is located with its receiving mouth at or near the rear end of the
partition, so that sound waves, impinging upon said reflecting surface, will be directed
towards and operate upon said receiver.
In the present instance, the receivers are in the form of receiving trumpets having
their mouths flattened and concave to conform to the curvature of the concave side of
the_partition.
This form of receiver is preferred in that the mouth or entrance to the receiver is
brought into close proximity to the reflecting surfaco and stands at a slight angle to
the front edge of the partition, thereby exposing the minimum surface for the action
of sound waves approaching the partition from the opposite side of the longitudinal
axis. Other forms and kinds of acoustic receivers may be substituted for the
trumpets shown, such for example as telephonic transmitters, but for ordinary use, [
prefer trumpets.
It is not essential, though desirable, that the partition and receivers be mounted to

page_text: move in unison about the same axis, as they may, if desired, be arranged to move
about independent axes. It is, however, necessary that they should both be inovable
to bring them to face the direction from whence the sound proceeds, and, also, that the
partition should be movable laterally in the are of a circle either with or independently
of the receivers and about a pivot, intermediate the two receivers so as to cause the
front portion of the partition to alternately uncover or expose one receiver, and, at the
same time, throw the other into the acoustic shadow.
The front face or edge of the partition is preferably formed flat or at an angle to
the planes of the reflecting surfaces, so that when the partition stands at but a slight
angle to the direction of the sound waves one of the flattened receivers will be protected,
the edge of the partition serving to intercept or cut off the sound waves.
Each receiver B is provided with a suitable conductor through which the sounds
received by or acting upon it may be transmitted to the observer, and in the apparatus
illustrated, wherein trumpets are employed, each of the latter is provided with a
conveying tube c terminating in an ear piece or receiver c¹.
The conveying tubes c may be contained in part within the hollow shaft C, as
shown, said tubes being connected at one end to the receiver and at the other to the
ear piece.
When thus arranged, that is to say, when the conductor is carried through the
shaft upon which the partition is supported, one of the internal tubes is arranged to
open through the side of the hollow shaft C above the other, as shown in figure 4,
and the outlet of each of said tubes c communicates with the interior of a resonator C¹,
preferably surrounding the shaft C, and the flexible tubes attached to the ear
pieces cand cach connected at one end to the outlet of one of said resonators.
The resonators serve as collectors and amplify the sounds transmitted so that they
can be plainly heard and distinguished as the shaft rotates to change or adjust tho
position of the partition.
The two ear pieces c', may, for convenience, be connected by a spring c³ serving to
clamp and hold them in contact with the ears of the observer, leaving his hands free
to manipulate the partition A.
The shaft C is supported at its lower end in a step bearing or bracket e and
passes vertically through a bushing or bearing e, to steady the apparatus and
permit of a free pivotal motion and a hand wheel or equivalent device is secured
to the shaft to facilitate the operation of turning and adjusting the apparatus.
It is desirable that the observer should be isolated or protected as much as possible
from the direct action of the acoustic signals transmitted through the atmosphere,
as bis attention must necessarily be given to the sound signals transmitted through or
by the receivers B, and it is perhaps equally as desirable that he should be protected
from the wind and weather, both of which may tend to impair or affect the organs of
hearing.
With a view to securing the requisite isolation and protection of the observer,
and thereby increase the efficiency of the service to be performed, the receiving
portion of the apparatus, that is to say, the ear pieces or other devices through
which the signals are delivered to the observer, are located under cover below the
deck or within a deck house or cabin and the shaft C carrying the partition and
receivers B, is projected vertically through the deck or roof D to which the upper
bearing c is secured.
As thus arranged the partition or vane A, together with the receivers B, B, are
located and sustained above the deck or roof D and are exposed to the direct action of
sound waves traversing the atmosphere, while the observer is located below the deck
or roof, in comfortable quarters and can readily rotate or oscillate the partition A
with its attachments by means of the hand wheel or other devices, at the same time
listening for sounds conveyed through the conductor from the receivers D, one of
which, say that on the left of the partition, being in communication with his left ear
and the other in communication with his right ear.
The resonators C" are held stationary and the shaft is permitted rotary motion

page_text: within them so that in whatever direction the shaft is turned each tube c will be
maintained in open communication with its resonator.
The manner of operating the apparatus is, briefly stated, as follows:
The observer being called upon or directed to ascertain the position of the object or
station from which the acoustic signals are transmitted or reflected, he first applies the
ear pieces so that he can distinguish the sounds transmitted through the receivers B, B,
and, grasping the band wheel, turns the shaft and with it the partition, until he hears
the sound proceeding through one of the receivers B, thereby indicating that the faco
of the partition adjacent the receiver is facing the signal station, but at a greater or
lesser angle to the line of movement of the sound waves.
Having obtained the general direction in which to look for the signal he continues
to move the partition around until the sound is rendered operative upon the other
receiver B, thereby indicating that he has passed the signal station, as the sound waves
which before operated on one side, say the right, are now received on the other, or left
side of the partition.
He now knows that the signal station lies at some point intermediate the positions
in which the right hand and left hand receivers B responded.
To ascertain more accurately the exact direction of the sound waves and the position
of the signal station, he proceeds to rapidly vibrate the partition in the arc of a circle
between the two extremes, gradually diminishing the excursions of the partition while
continuing the alternations of the sounds transmitted through receivers B, until
finally a point is reached when both receivers B respond equally and the partition is
brought to rest with its longitudinal axis in line with the signal station whose position
was to be found.
Experience has demonstrated that by this mode of procedure and with an apparatus
constructed in accordance with the principles explained, it is possible to ascertain with
great accuracy the position or point of the compass from which the acoustic signals
heard at the receiving station are transmitted.
The sensitiveness of the apparatus and its accuracy in locating the direction of the
signals is increased when the vane or partition is rapidly vibrated to present the
reflecting side alternately towards the signal station, as by this means the apparent
effect on the receivers is augmented by simultaneously throwing one receiver within
the influence of the sound waves and the other into the acoustic shadow, thus pro-
ducing rapid transitions from sound to silence at the point where the observer is
situated and listening, so that he can readily detect when one receiver is brought into
action and the other thrown out of action and in this way by gradually narrowing the
range of motion, he is enabled to quickly arrive at the neutral point, with the partition
pointing towards the place from which the signals are transmitted.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is:
1. A sound locating apparatus provided with two acoustic receivers each having a
separate sound conductor, and a vertical partition interposed between said receivers,
and movable laterally about a vertical axis.
2. A sound locating apparatus provided with two acoustic receivers and an inter-
posed laterally movable vertical pariition having a concave reflecting surface in proximity
to each of said receivers.
3. An apparatus, such as described, provided with a laterally movable vertical
partition with parallel reflecting surfaces, and two acoustic receivers, one on each side
of the partition, said receivers having vertically elongated mouths or openings in
proximity to the reflecting surfaces of the partitions.
4. An apparatus, such as described, provided with a laterally movable partition with
concave reflecting surfaces, and acoustic receivers, one or more for each reflecting
surface, provided with concavo-convex months in proximity to said reflecting
surfaces.

page_text: 5. The acoustic receivers and an interposed vertical partition mounted upon a
vertical shaft.
6. The acoustic receivers and interposed vertical partition mounted upon a vertical
shaft, said receivers being connected to separate sound conductors contained within
the shaft.
7. The vertical shaft carrying the two acoustic receivers and an interposed vertical
partition and provided with separate sound conductors each connected to one of the
receivers, and the resonators surrounding said shaft and communicating with the sound
conductors carried thereby.
8. A vertical shaft mounted to turn in bearings and provided with two acoustic
receivers separated by a vertical partition, two resonators with separate ear pieces
and two sound conductors, each of the latter communicating at one extremity with
one of the acoustic receivers and at the opposite extremity with one of the resonators.
9. A sound locating apparatus, such as described, comprising two acoustic receivers
and an intermediate vertical partition mounted to turn about a vertical axis, with
separate sound conductors extending from each of said receivers to an enclosed
observation chamber.
10. A sound locating apparatus, such as described, consisting, essentially, of two
acoustic receivers and an intermediate partition the whole mounted to rotate about a
vertical axis and located in a position exposed to sound waves traversing the atmo-
sphere, with devices for controlling the movement or position of said apparatus, and
separate sound conductors connected to the two receivers, said controlling devices and
the receiving portion of the sound conductors being located within an enclosed
observation chainber.
11. A sound locating apparatus, such as described, the same consisting of two
acoustic receivers and an intermediate vertical partition mounted upon a vertical shaft
passing through the deck of a vessel or the roof of a chamber, said shaft being provided
with devices by which the observer can rotate it, while the acoustic receivers are
placed in communication with the observer through separate sound conveyors.
12. Two acoustic receivers and an intermediate vertical partition the whole centrally
supported upon a vertical axis.
13. The described mode or method of locating the point from which acoustic
signals proceed by vibrating a vertical partition in front of isolated acoustic receivers
provided with separate sound conveyors.
Dated this 19th day of March 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.