Improvements in Screens for Eophones or Sound Receiving Instruments.
Year: 1897

page_text: Date of Application, 31st May, 1897-Accepted, 10th July, 1897
COMPLETE SPECIFICATION.
Improvements in Screens for Eophones or Sound Receiving
Instruments.
1, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Lewis Nixon, of Crescent Ship Yard,
City of Elizabeth, State of New Jersey, United States of America, Ship Builder, and
Charles Monsou Raymond of No. 20 Fifth Avenue, City of New York,
State of New York, United States of America, Manufacturer) and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
The object of this invention is to protect sound receiving instruments from the
rush of air to which they are frequently exposed, and prevent the shrill whistling
around the sharp edges of the instruments which is caused by the wind and which
interferes materially with the observation.
According to this invention there is provided a skeleton frame or cage having
stretched thereon a covering of silk or other material of similar nature with which
to protect the instrument and prevent the passage of the wind into the interior of
the cage sufficient to cause a whistling effect to be produced, and at the same time
allow the free transmission of sound.
In order that the invention may be clearly understood I will describe the same
with reference to the accompanying drawing of which Fig. 1 is a perspective view of
a protecting cage or screen made in accordance with this invention.
Figure 2 is the stationary combing or curb to which the screen is attached.
Figure 3 is an enlarged transverse section of the roller for holding the ends of, and
stretching the silk or like material around the cage.
Figure 4 is a tranverse vertical section through a portion of the screen or cage and
its supporting combing or curb.
Figure 5 is an elevation of the stretching roller.
Figure 6 is an elevation of the shutter contained in the said roller.
Figure 7 is a sectional detail showing the manner in which the upper end of the
roller is arranged in the top part of the cage.
Figure 8 is a sectional detail illustrative of the means for vertically tightening the
silk or like covering.
Figure 9 is a view of a portion of one of the bands by which the top and bottom
edges of the covering are held.
Figure 10 is an elevation of the meeting ends of the covering, shewing the rods
which are fitted to those ends and the band which is fitted to the top edge of the
silk.
The eophone or sound receiver is an instrument designed to receive, magnify and
intensify sound, thus enabling noises so faint as to be nearly or quite inaudible to
the unaided ear, to be distinguished and heard with ease. An instrument of this kind
is described in Letters Patent No. 4301 dated March 19th 1890. The instrument is
one which is designed for use on ship-board and in other places where it is exposed
to the wind which frequently blows with such force as to interfere inaterially with

page_text: the efficiency of the instruinent. It is to protect instruments of this description
from this objectionable rush of wind that the screen shewn in the drawing is
designed.
It consists of a cylindrical openwork frame or cage B closed at top and bottom
against the wind, and has stretched around it a covering of silk or equivalent material,
which shields the instrument placed within the cage, from the force of the wind, but
does not interfere with the free transmission of sound.
It is preferred to support the cage B by any suitable means upon a cylindrical
combing.or curb C which is closed at the bottoin, and does not reach up so high, as
the lower edge of the sound receiver. In the present instance the cage and combing
or curb are held together by bolts a the heads of which pass down through the enlarged
parts of slots in the top edge of the combing and then by turning the cage so as
to cause the heads of the bolts a to come under the narrow portions of slots b the cage
will be securely locked to the combing, while at the same time the arrangement
is such that the cage can readily be removed from the combing whenever
desired.
The cage itself consists of top and bottom rings c, d, connected by vertical bars e,
the rings as well as the bars being of any suitable niaterial.
The top of the cage is closed by a lid which rests upon the upper ring c.
D is a covering of silk or other suitable material which will oppose the forcible
entrance of air to the interior of the cage without however interfering with the free
transmission of sound. This covering is of a width to extend from the top to
the bottom of the cage, and is long enough to extend around the cage. The meeting
ends of this covering are suitably held, and means are provided for stretching it taut
around the bars c of the cage. It is preferred to employ for this purpose a hollow
stretching roll or drum E (Figure 3) suitably mounted at its ends in the top and
bottom rings c, d of the cage so that it may be capable of rotation. It has in it a
longitudinal slot or opening g and it contains a shutter h, which can be moved to
open or close the slot as desired. The shutter is held in place by studs which pass
through angle slots 2 in the stretching roll, and have heads which overlap the
edges of the slots so as to hold the shutter up against the inner face of the roll. On
the upper end of the shutter is a stem h³ which projects through the upper end of
the roll, and is formed as a handle which can be taken hold of to manipulate the
shutter.
In the meeting ends of the silk or like cover are formed pockets i for the
reception of rods. These rods are placed in the pockets, and then they with their
pockets are inserted into the roll E, through the open slot g after which the shutter h
is manipulated so as to close the slot, as shewn in Figure 3, the ends of the silk or
like cover being firmly held in the stretching roll.
When the cover is thus held, it can be readily stretched by rotating the roll E,
which will have the effect of drawing the cover tightly around the cage, the surplus
silk or the like being wound upon the roll. To prevent the roll from unwinding
it is provided at its lower end with a ratchet kengaged by a spring pawl (Figure 4)
attached to the lower ring of the cage.
The stretching roll E is operated through a suitable opening in the lid f, in which
opening the upper end of the roll fits snugly so as to prevent entrance of air. The
top of the roll E, is squared, for the reception of a suitable winch or wrench by
which the roll can be turned.
It is necessary that the cover should be held not only at its ends, but at its top anda
bottom edges. To this end it is provided at each edge with a pocket m of stout material,"
and in the bottom ring of the cage as well as in the lid f at the top, is formed an
annular peripheral groove o. In each pocket m is inserted a metal band n, which fits
into the grooves 0.
These bands are drawn tight by turn buckles n' with which
they are provided, thus clamping the edges of the cover tightly into the grooves o
as indicated in Figure 4. In light weather draw strings may be used instead of
the bands n.
The cover should be stretched not only lengthwise but in the direction of its

page_text: width. For the latter purpose the part of the cage to which the upper edge of the
cover is secured-in this instance the lid is made capable of being moved towards
and from the lower ring to which the bottom edge of the cover is made fast. To
this end the lid is provided with screws p which screw into and through the upper
ring c, the heads of the screws being readily accessible for the purpose of manipulating
them, from the top of the lid as indicated in Figure 8. By turning these screws in
the proper direction the lid f can be lifted away from the ring c, thus stretching the
cover in the direction of its width.
The combing or curb C as well as the cage are independent of the sound receiving
instrument which they surround, and are sufficiently removed from the latter not
to interfere with its movement. There are no projections on either the combing or
the cage to catch the wind.
.
Having now particularly described and ascertained the nature of this invention
and in what manner the saine is to be performed, I declare that what I claim is :-
1. A screen for eophones or sound receiving instruments, adapted to be placed
around, and surround the instrument, the said screen being closed at the top and
bottom and having an open work frame or periphery around which is stretched a
covering of silk or other like material to prevent the wind from striking the
instrument, without interfering with the free transmission of sound, substantially as
hereinbefore described.
2. A screen for eophones or sound receiving instruments adapted to be placed
around, and surround the instrument, closed at the top and bottom and baving an
open work periphery around which is placed a covering of silk or like material to
prevent the wind from striking the instrument without interfering with the free
trausmission of sound, and provided with means for stretching the silk both
lengthwise and crosswise upon and around it, substantially as hereinbefore
described.
3. In a screen for eophones or sound receiving instrument a cage adapted to be
placed around and surround the instrument closed at top and having an open-work
periphery around which is stretched a covering of silk or other like material, to
prevent the wind from striking the instrument, without interfering with the free
transmission of sound, in combination with a supporting combing closed at the
bottom, on which combing the cage rests and to which it is detachably connected
so as to permit it to be removed bodily from over and around the instrument
whenever desired, substantially as hereinbefore described.
Data thin 14 da
8. 1005