Improvements relating to Telephones.
Year: 1893

page_text: Date of Application, 16th June, 1893
Complete Specification 'Left, 7th Mar., 1894-Accepted, 28th Apr., 1894
Improvements relating to Telephones.
I PARNELL RABBIDGE of Invergary, Crouch Hall Road, Crouch End in the
County of Middlesex, Electrician, do hereby declare the nature of this invention
to be as follows :-
The object of this invention is to simplify the construction and improve the action
of telephonic instruments, more particularly for private use.
To this end, the instrument consists of a transmitter and a receiver, which are
rigidly connected together in such a manner that they may be used simultaneously.
The receiver is also made to act as the alarm or call, and an automatic gravity
switch is employed by which the various circuits are closed as and when required.
In carrying out this invention, the transmitter may consist of a metal box
provided with a screw cover to hold a diaphragm in position. The cover also
carries a suitable mouthpiece.
In rear of the diaphragm is an adjustable microphone, which may consist of an
india rubber or other ring enclosing a quantity of granular carbon, and held in
position by a screw working in a metal socket carried by a slab of insulating
material attached to the transmitter case.
The transmitter is secured by a (preferably) hollow connection with the receiver,
which may consist of a metal case provided with a screw cover, which secures a
diaphragm in position, and also carries the ear piece.
Inside the case, and preferably centrally thereof, is a bobbin or electro magnet,
the core of which is at one end firmly attached to the case, and at the other end
projects beyond the bobbin, and close to the diaphragm.
Between the bobbin and the diaphragm, and arranged laterally of the core, is
a light spring armature, which is carried by an insulating piece secured to the
case, and partially enclosing the bobbin. This armature is put into connection
with the metal case in any suitable manner.
Carried by the same insulating piece, is an adjustable contact screw, which is
placed in electrical connection with the alarm.
As the current passes, the spring armature is caused to vibrate, and make and
break contact, which magnetizes the magnet intermittently, and thus the diaphragm
is caused to vibrate and give out a musical note, to serve as a call or alarm, so
that the receiver is made to serve the double purpose of receiver and alarm
or call.
.
The gravity switch, which will be placed inside the rigid connection between
the transmitter and receiver, when hollow, consists of a tubular vessel containing a
globule of mercury, and provided with the necessary internal contact points for
closing the circuit to the alarm, or the telephone circuit, as may be required.
By the improved construction, all the parts of a telephone instrument are
arranged and combined, with one handle, in a compact and simple form, and the
necessity for a complicated instrument to be fixed to the wall, or in any other
suitable position, is entirely avoided.
In some cases, it may be desirable to employ the receiver not only as the receiver
and call, but also as the transmitter, in which case the separate transmitter would
be dispensed with.
.
Dated this 16th day of June 1893.
NEWTON & SON,
Agents for the Applicant.

page_text: Improvements relating to Telephones.
I, PARNELL RABBIDGE of Invergary, Crouch Hall Road, Crouch End in the
County of Middlesex, Electrician, 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:―
The object of this invention is to simplify the construction and improve the
action of telephonic instruments, more particularly for private use, as, for instance,
in offices or private houses, to supersede speaking tubes.
To this end, the instrument, which is in a portable form, consists of a trans-
mitter and receiver connected to opposite ends of a hollow handle, of such a
length, that when the receiver is in position at the ear, the transmitter will be in
close proximity to the mouth of the user. The receiver may be made to act also
as the alarm or call, and an automatic gravity switch is employed, by which the
various circuits are closed, as and when required, by simply turning the instrument
upside down.
In the accompanying drawing I have shewn the telephone instrument in its
simplest and best form, by way of example,
Fig. 1 being a longitudinal section, and
Fig. 2 a front view, with certain covering parts removed, as will be more
particularly referred to.
.
In the position shown in the drawing, the instrument is supposed to be not in
use, that is to say, hanging on its hook by the eye at the top, the call being in
circuit.
A is the receiver, and B the transmitter, which are fixed at opposite ends of a
hollow handle C, preferably of vulcanite or other insulating material, in the manner
shown.
The receiver A, which also acts as the electric call, as will be hereinafter more
particularly described, consists of a metal box A, containing a bobbin a, the core
of which is, at one end, a¹, securely fixed into the bottom of the box, the other
end a being prolonged some distance beyond the bobbin a. One end of the reel
on which the wire is wound is made of sufficiently large diameter to fill the case A,
as seen at a*, and being made of insulating material, other parts of the instrument
may be attached thereto, and supported thereby. a³ is a metal diaphragm, which
is held in position (close to the core end a²) by a ring a' and the cap a³, which cap
screws onto the case A, and grips the ring a and the diaphragm between itself and
the edge of the case A. The cap a carries also the ear piece a (or mouthpiece,
when the receiver is used also as transmitter), an opening in the cap allowing the
sound waves to reach the ear or the diaphragm, as the case may be. Between the
plate aand the diaphragm a³, is arranged a spring armature contact breaker a',
which is fixed in a stud as carried by the plate a*. This spring a' is normally in
contact with an adjustable screw a³, mounted in a stud a, also carried by the
plate a*.
The transmitter B consists of a vulcanite or other suitable box B, in the bottom
of which is fixed a plate b, centrally of the box, and secured to the plate is a metal
box & containing a carbon block Outside this box 6', is an india rubber ring 63,
so arranged that it will almost touch a carbon diaphragm b.
A space will be left
between the diaphragm and the block 2, which is loosely filled with grains
of carbon b³. The diaphragm is held between two brass rings ', which are
screwed down onto the edge of the box B by screws, as indicated by the screw
holes 67, Fig. 2. If desired, the whole may be covered by a perforated metal
cap, as shewn in Fig. 1.

page_text: The loose grains of carbon, in whatever position the instrument is held, will
fall to the lower side, and pile themselves up, so to speak, thus automatically
bridging over the space between the carbon block and the diaphragm, and ensuring
a perfect contact.
In Fig. 2, the diaphragm &, ring 7, and cap 68, are removed. 6° and 61° are two
terminals fixed to the bottom of the box B.
The handle C is preferably formed in two parts, the second or cover part C₁
being secured by screws cc to the main part C. In the hollow of the handle C,
is contained a gravity switch D, which consists of a small elongated glass vessel
containing a globule of mercury. The contact points consist of wires which may
be blown in the glass, one point, 1, passing through the vessel from end to end,
while the other points, 2 and 3, just enter therein at the opposite ends. These
several wires are attached to the binding screws c', c³, and c³ (Fig. 2) respec-
tively, and serve to secure the switch in position in the handle C, a fourth
binding screw being provided to secure one end of a the microphone wire.
case A.
X and Z, Fig. 2, are the line wire and return wire respectively, both of
which may enter the case B, at the same opening, the line wire X passing to
screw b, and thence by screw c¹ to switch point 1. The earth wire Z passes to
screw, and thence, through handle C, to the exit end of bobbin wire in
Switch point 3 connects by wire W, with screw c², and thence to
plate b of microphone or transmitter. Switch point 2 connects by wire V with
Screw, and thence to stud a¹0 of adjustable screw a°. The inlet end of bobbin
wire connects with the stud a", to which also is attached the wire T, which
connects through screw e to the ring 6 of transmitter.
When it is desired to operate the call, the instrument must be hanging up,
or held in the position shewn in the drawing, that is to say, with the trans-
mitter B uppermost. The battery being shunted into circuit in any convenient
manner, the current enters at X, passes through switch D to screw a' in
receiver A; thence, through spring armature a', to bobbin a, and out by return
or earth wire Z. As soon as magnet is energised, spring armature a² is attracted,
and withdrawn from contact with screw a'. The circuit is thus broken, and the
magnet becomes demagnetised, so that the armature a springs back into contact
with screw a', thus again completing circuit, which is again almost simultaneously
broken.
Rapid vibration of the spring armature is thus set up, and also rapid vibration of
the diaphragm a³, which gives off a musical note, so long as the instrument is
hanging on its hook, or is held in the position shown. When the instrument is
taken down for use, and its position reversed, the globule of mercury in the gravity
switch will be found at the other end.
The current will then pass as follows:-Enters at X, and passes successively
switch points 1 and 3, to plate b, carbon 62 and 6, diaphragm, ring be of
transmitter B; thence by wire T to stud a and bobbin a of receiver A, to earth
by wire Z. Thus, it will be seen, both the receiver A and transmitter B are in the
circuit, and by holding the receiver A close to the ear, and the transmitter B near
the mouth, conversation can be carried on without difficulty.
I would here remark, that the microphone or transmitter above described is simple
and effective, but I do not intend to confine myself to this exact form; as any micro-
phone may be used for the purposes of my invention; nor do I wish to confine
myself to the special form of receiver and call, or to the special form of switch, as
these may be varied without departing from the nature of my invention, the
essential feature of which is, combining in one and the same simple and compact
instrument, all the parts which go to produce a telephone, namely, a receiver, a
transmitter, a call or alarm, and a switch, which, it will be seen, is very satis-
factorily accomplished, by way of example, in the instrument shown in the drawing.
By the use of such an instrument, the necessity for a complicated instrument to be
fixed to the wall, or in any other position, and, in two or more separate parts, is
entirely avoided.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. As a new article of manufacture, a portable telephone instrument, which
consists of a receiver, a transmitter, an alarm or call, and a switch, arranged and
combined in one and the same instrument, as set forth.
2. A telephone receiver in which the diaphragm is vibrated by an interrupted or
intermittent current of electricity, thereby emitting a sound which serves as an
alarm or call, in combination, in one and the same instrument, with a transmitter
and a switch, as herein set forth.
3. The construction of the combined electric alarm or call and receiver for
telephones, substantially as herein described and shewn in the accompanying
drawing.
4. The construction of microphone or transmitter for telephones, substantially as
herein shewn and described.
5. In telephonic apparatus, the combination of a portable transmitter with a
gravity switch, as set forth.
Dated this 6th day of March 1894.
NEWTON & SON,
Agents for the Applicant.