IMPROVEMENTS IN AND RELATING TO MECHANICAL TELEPHONES
Year: 1884

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co Patent Agents,
Southampton Buildings in the County of Middlesex do hereby declare the nature
of my Invention for "IMPROVEMENTS IN AND RELATING TO MECHANICAL
TELEPHONES" 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 the construction of appliances for transmitting speech,
known as mechanical telephones, and it consists partly in insulating the operative
parts of the device from the box or case in which they are enclosed, whereby all
sounds or vibrations coming from the wall of the building, or wherever the
instrument is mounted, are effectually cut off from the said operative parts; also
in insulating the whole device from the wall, or whatever it is mounted upon.
It further partly consists in providing a door or cover for the mouth of the
transmitter, which door or cover is adapted. to move beside the said mouth when
it is desired to use the telephone, and which, when a conversation is completed may
be thrown up and cover the said mouth.
In the accompanying Drawing,
Figure 1 is a perspective view of a set of mechanical telephone apparatus,
embodying the said Invention.
Figure 2 is a front elevation of the transmitter-box detached, with the door or
cover closed.
Figure 3 is a view similar to Figure 2, except that the door or cover for the
mouth of the transmitter is open;
Figure 4 is a horizontal sectional view, looking downwardly from the dotted
line 2, 2.
Figure 5 is a vertical sectional view looking toward the right from the dotted
line y, y, and
Figure 6, is a section through the corner of the base-board showing the manner
for connecting it to the wall.
Similar letters of reference indicate corresponding parts throughout the Drawing.
A indicates the base-board on which a set of telephone apparatus is mounted;
B, the call-signal box used with this tolephone; C, the transmitter-box; D, the
Price 6dl

page_text: receiving telephone, and E, a door or cover by which the mouth of the transmitter
is closed.
The part A is simply an ordinary base-board on which telephone apparatus is
mounted. It is, however, secured to the wall, or whatever part of the building or
other structure upon which it is mounted, in a peculiar manner.
The holes
through which the screws a pass are made considerably larger than the said
screws, and a piece of soft india-rubber tubing or other non-resonant material a¹
is inserted therein. Interposed between the base and that portion of the structure
to which it is attached is a washer a² made of felt or other non-resonant material,
and a small washer a³, under the head of the screw a. Thus it will be seen that
the screw is kept entirely from contact with the base-board A, and any vibrations
coming from the structure on which the apparatus is mounted, will be taken up
by the non-resonant material surrounding the screw, and not by the apparatus, or
the base-board as has been usual.
The call signal box B is an ordinary magneto call-signal bell, and forms no part
of the present Invention.
In the transmitter-box C, is mounted the mouth piece C¹, on the inner end of
which is a wooden diaphragm-support C² between which, and the metallic cap C³,
is secured the diaphragm C The inner faces of these two parts C³, and C³, are
hollowed out so as to form a chamber for the diaphragm, as shown in Figure 5.
This diaphragm consists preferably of a metal plate c, having a backing c¹ of
pasteboard, or other like material, and a ring c² and washer c³,
on its
upper
surface of a material similar to the backing. These several parts are tightly
clamped within the chamber just described between the edges of the parts C³
and C. A hook or eye c¹ is secured to the centre of the diaphragm passing
through the same, as shown, and forms a means whereby the line-wire C³, is
attached to the instrument. Between the outer surface of the part C3 and the
inner surface of the box or casing is placed a piece of heavy felt or other like
material C which keeps said part C3; from contact with said box or casing.
Around the other sides of the operative parts of the instrument a non-resonant
substance C is tightly packed, which takes up all the vibrations coming from the
wall of the building or wherever the instrument is mounted, and insulates the
operative parts of the instrument therefrom. The substance which I prefer to
use for this packing is mineral wool, it being a cheap and effective substance for
the purpose.
By the use of these insulating agents. arranged as specified, I have found by
practical tests that the efficiency of the apparatus is much increased, as practically.
no sounds except those intended to be transmitted are allowed to come into
the instrument under this arrangement.
The hand or receiving telephone D is connected to a projecting portion on the
metal part C3, by a flexible piece of tubing D'. This however forms no part of
my present Invention.
Heretofore considerable difficulty has been experienced in the use of mechanical
telephones, especially when several were used on the same line, by reason of
extraneous sounds, such as the noise of vehicles from the streets, and any incidental
noises that might be made in its vicinity, entering the transmitter and passing
along the wire to the other instruments on the line, thus not only confusing the
voice sounds, but decreasing the efficiency of the apparatus generally. It has also
been difficult to ensure the privacy of conversations which were carried on in
proximity to apparatus of this character, it having been possible for any one at the
other end of the line, by listening at the telephone, to hear such conversation,
which, as will be readily understood was frequently very objectionable.
These objections are overcome by the use of the door or cover E which is
preferably mounted on a pivot e, on the face of the transmitter-box, and is adapted
to move up and down on said pivot. It is in the form of a disc of sufficient size
to cover the mouth, of the transmitter, and is preferably lined with a soft,
non-resonant substance e³, (usually felt) which serves to make a tight joint over.

page_text: the mouth of the transmitter. It has a projecting arm E¹, which, through a cord
or chain d, is connected to the hand telephone D, through which, as the said
telephone is dropped into the position shown in Figure 1, the said door.or cover is
operated to cover the mouth of the transmitter as shown. It also has a projection E³
which, as. it is brought into a closed position, comes in contact with a stop or
catch e² and is thereby stopped and held at the proper point.
This door or cover is operated as follows: When the hand telephone is raised to
the ear, thus relieving the said cover and the arm E¹, from the weight thereon the
said cover drops into the position shown in Figure 3, thus leaving the mouth of
the transmitter open for use. When the conversation is completed and the hand
telephone is dropped into the position shown in Figure 1, its weight overbalances
the weight of the door or cover E, and throws the latter into the position shown
in Figures 1 and 2 thus covering the mouth of the transmitter, and preventing any
sounds from entering therein.
The general object and effect of my whole Invention is to shut out sounds from
mechanical telephones, other than those intended to be transmitted thereby.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
First. The combination with the case and operative parts of a mechanical
telephone, of a soft non-resonant substance interposed between the said operativo
parts and the said case, substantially as described and for the purposes specified.
Second. The combination with the box or case of a mechanical telephone, and
the operative parts enclosed therein, of a soft, non-resonant substance interposed
between the parts covering the diaphragm and the side of the case toward which it
is drawn, whereby vibrations from the said case are intercepted or cut off from the
said diaphragm, substantially as set forth.
Third. The combination, with the casing and operative parts of a mechanical
telephone, of a soft non-resonant substance such as mineral wool packed into the
said case about the said operative parts, whereby the said operative parts are
insulated from the said case, in the matter of receiving sounds therefrom,
substantially as set forth.
Fourth. The combination with telephone apparatus and the structure upon which
it is mounted, of means of attaching the said apparatus to the said structure,
consisting of ordinary screws or nails, and soft non-resonant material surrounding
the said screws or nails, substantially as set forth.
Fifth. The combination, with the base board A, of a telephone apparatus, of the
screws or nails a for connecting the same to the structure upon which it is mounted,
and the soft, non-resonant parts a', a², as interposed between the said screw and
the said base-board, whereby vibrations coming from the structure are cut-off from
the apparatus, substantially as set forth.
Sixth. The combination with the fastenings by which telephone apparatus is
secured to the structure upon which it is mounted, of soft non-resonant material
interposed between the said apparatus and the said fastenings, substantially as
described and for the purposes specified.
Seventh. The combination with the transmitter of a mechanical telephone, of a
door or cover whereby the transmitter may be closed when not in use, and
conveniently opened for use, substantially as set forth.
Eighth. The combination with the transmitter of a mechanical telephone, of a
door or cover pivotted alongside the mouth of the transmitter, and adapted to be
moved, and the transmitter thus opened or closed at the will of the operator,
substantially as set forth.
Ninth. The combination with a telephone transmitter, of a door or cover E,
pivotted alongside the mouth of the transmitter in such relation thereto that the
said transmitter may be closed thereby, or left open, substantially as set forth.
Tonth. The combination of the telephone transmitter, the hand telephone, a door
or cover pivotted alongside the mouth of the transmitter, and a connection between

page_text: the said door or cover and the said telephone, whereby, when the said telephone is
dropped into the position it occupies when not in use the said door or cover will be
operated to close the mouth of said transmitter, substantially as set forth.
Eleventh. The combination of the transmitter of a mechanical telephone, the
receiver, the door or cover E mounted on the pivot e and provided with the arm E¹
and a cord or chain d connecting the said arm to the said receiving telephone,
substantially as described and for the purposes specified.
Dated this 5th day of Aucunt 1001
HASELTINE, LAKE & Co.,
For the Applicant.