Improvements in or connected with Telephonic Instruments
Year: 1899

page_text: Date of Application, 10th Jan., 1899-Accepted, 25th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in or connected with Telephonic Instruments,
A communication from abroad by THOMAS BARNET, Architect, care of John McVey
Baird, Eglinton, Glebe Point, Sydney, New South Wales.
I, ARCHIBALD LAIDLAW BAIRD, of 8, Upper Bedford Place, London, of no
occupation, 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 certain improvements in apparatus for recording the
duration of time the telephone instrument of a subscriber to an exchange system is
in use or for otherwise recording the duration of time a telephone is used, the object
being to provide a simple mechanical form of apparatus, which is easily applied to a
telephone and which will be certain in its action.
The invention has been specially devised with a view to charge for the use of the
telephones by time, so that a subscriber who has but little use for his telephone will
not be called upon to pay at the same rate as the subscriber whose instrument is
in constant use. To this end the lever switch of the telephone is connected with
a clock or other mechanism which shall be inoperative when the telephone is not
in use, but as soon as the receiver is lifted from the lever, the clock work shall
commence to operate and will thus register the extent of time that the instrument
is being used. The apparatus is so arranged that the up and down movement of the
lever switch shall wind up the clock work and thus the operation will be almost
entirely automatic.
In the accompanying drawings:-
Figure 1 is a front elevation, partly in section, of a telephonic instrument of
the Ericsson type, shewing the permanent magnets and with the clock work
arrangement introduced in the left hand corner.
Figure 2 is a side elevation of the clock work appliances.
Figure is a front elevation of the automatic releasing and winding gear.
Figure 4 shews the dial upon which the time the telephone has been in use may
be read.
Figure 5 is a detail shewing a small appliance which may be found useful in
starting the clock work when it is released from the control of the switch lever.
Figure 6 is a detail shewing an appliance for use in large establishments where
there is a minor exchange for inter-communication between the rooms in the
establishment and one connection with the central exchange.
The telephonic apparatus selected to illustrate the invention is an ordinary
"Ericsson" telephone, having the receiver and transmitter in one. This instrument
is one in common use in the Colony of New South Wales.
A is the switch lever provided with a hook a, on which the combined receiver
and transmitter is suspended. The position shewn is that assumed by the lever
when it is depressed by the weight of the combined transmitter and receiver, the
elevated position being shewn by dotted lines. B, is the clock work appliance

page_text: which may be made in any way that would be effective in carrying out the idea
involved in the invention. To one side of the clock work appliance will be attached
the hands and dials for recording the time, in any manner, such as is usually
adopted in recording meters. On another side of the clock work appliance is
placed the automatic winding gear. This consists of a ratchet wheel outside the
clock work case and connected to the spur wheel within the case.
These two, b
and b, revolve together loosely upon the counter-shaft 2. The lever arm C is
keyed at one end on to the countershaft while the other end is connected by the
insulated link c to the switch lever A. Articulated to the lever C is the pawl D
which is maintained in contact with the teeth of the ratchet b by means of the
spring d.
The spur wheel b will gear with the segmental pinion E which is keyed on the
axis e to which is connected the actuating spring that is enclosed within the
spring case F. The spur wheel E is made segmental in order to prevent overwind-
ing of the spring. The pawl 1 is provided with a tail piece d' which will impinge
against the stop d² (placed in any suitable situation) when the lever A is in its
elevated position, and thus the pawl D will be kept clear of the teeth of the
ratchet and the clock work apparatus will be free to revolve. When the switch
lever A is depressed the pawl D will be released from contact with the stop d²
and will re-engage with the teeth of the ratchet 6 thus arresting the movement of
the clock work.
-
The actuating spring is automatically wound in the following manner: -When
the conversation through the telephone is finished, the receiver is hung upon the
switch lever A, thereby depressing it. The pawl I will be released from contact
with the stop d² and will re-engage with the teeth of the ratchet b, while the weight
on the lever A will cause the ratchet to make a partial revolution backwards, equal
to the space of about two ratchet teeth. This backward movement will be com-
municated through the spur wheel and the segmental pinion E to the actuating
spring within the case F. The spring will therefore be potentially more powerful
by the amount of resilience represented by the space of two teeth on the ratchet.
Should the spring within the case F be run right down it may be re-wound by
working the lever A up and down. Or, in order that the clock work mechanism
shall be prevented from running down, should the receiver be left off the hook a, a
stop z is placed upon the side of the ratchet b which shall engage with the lever arm C
and thus prevent the ratchet and clock work from turning when the stop comes up
against the lever C.
Should it be found necessary to start the balance wheel H of the clock work,
the device shewn in Figure 5 may be employed. The lever arm G is firmly pinned
on to the counter shaft 62 and is provided at its outermost end with a small spring g
When the lever C is drawn up by the movement of the lever A, the lever G will be
depressed to the dotted position shewn in Figure 5, thereby giving a slight send or
impetus to the balance wheel H sufficient to start it oscillating. It is considered
that the balance wheel would start without this appliance, but it has been considered
advisable to shew in case of accidents.
J, Figure 4, are the recording dials which are constructed in a manner well known
and understood, being similar in all their main features with those employed in
any ordinary recording meter,
Figure 6 is an appliance which is used in minor exchanges for the purpose of
connecting the whole telephonic system of one establishment with the central
exchange. This consists of the plug K which is a common appliance. The lever O
embraces it and is kept against the shoulder k by means of the weak spring k
The plug K is pushed in until its bulbed end completes the circuit, at the same
time carrying with it the lever C thereby releasing the clock work mechanism.
When the telephone is rung off, the plug K will be pulled out allowing the lever C
by its pawl, to re-engage with the teeth of the ratchet and the movement of the
clock work apparatus will be arrested.
It has before been previously proposed to provide apparatus both electrical and

page_text: mechanical for indicating the time and number of telephonic communications and
the same is not broadly claimed herein but;
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is:-
1. In telephonic instruments, the combination with the switch lever A of a
clock work mechanism directly controlled thereby said mechanism having a dial
or dials for the purpose of cumulatively recording the time that the telephone
instrument is in circuit for conversational purposes, substantially as described.
2. In telephone instruments, the combination with the switch lever A of clock
work mechanism directly connected thereto and a dial or dials, which serve as a
time recorder, and means for arresting the movement of the mechanism when the
telephone is not in use, and for releasing the same when the circuit is completed
for conversational purposes by the movement of the lever A as herein set forth.
3. In telephone instruments the combination with the switch lever A, of a clock
work apparatus and a dial or dials, as a time recorder, and means whereby the
main spring of the clock work may be automatically wound up by the movement of
the lever A at the close of the conversation as herein set forth.
4. In telephonic apparatus, the combination with the appliance by which the
circuit is closed for conversational purposes as in Figure 6, of a clock work
mechanism and a dial or dials, to serve as a time recorder for the purposes herein
set forth.
5. In telephonic apparatus, the combination with the appliance by which the
circuit is completed for conversational purposes, as in Figure 6, of clock work
mechanism and a dial or dials, to serve as a time recorder, and means for arresting
the movement of the mechanism when the appliance is not in use, and for releasing
the same when the circuit is completed for conversational purposes, as herein set
forth.
6. In telephonic apparatus, the combination with the appliance by which the
circuit is completed for conversational purposes, as in Figure 6, of clock work
mechanism and a dial or dials, to serve as a time recorder, and means whereby
the main spring of the clock work may be automatically wound up when the
circuit, for conversational purposes, is broken, as herein set forth.
7. The general arrangement, construction and combination of parts of the
cumulative time indicator and recorder to be used in combination with telephones,
as herein described and for the several purposes herein set forth.
11
101
1
e T
1000
PHILIP M. JUSTICE,
Chartered Patent Agent, London, for the Applicant.