Improvements in Automatic Telephone Devices.
Year: 1889

page_text: Date of Application, 20th Sept., 1889
Complete Specification Left, 19th July, 1890-Accepted, 20th Sept., 1890
PROVISIONAL SPECIFICATION.
Improvements in Automatic Telephone Devices.
I, CARL GUST. HOFFMANN of Wachter-Strasse 5, Leipzig, in the Empire of
Germany. Electrician, do hereby declare the nature of my invention to be as
follows:-
This invention relates to automatic public telephone-apparatus and consists in the
main of the speaking-apparatus, of the mechanism for examining the coin and of the
box, and consists in the combination of a telephone system with a coin examining
apparatus and a clock-mechanism situated in the exchange-station in such a manner,
that by the insertion of a certain coin into the apparatus a draw-rod is released and by
pulling the same by means of lever-connections the telephones are liberated so that a
call is automatically effected to the exchange-station, which establishes the desired
connection with the public speaking station which is then connected with the wire of
the subscriber by the pressure of a button and at the same causing the stoppage of a
wheel moved by a clock-mechanism during any desired interval (5 minutes) by a
lever which at the termination of this time, raised by another lever, establishes again
the earth connection and thus interrupts automatically the connection of the public
speaking station with the subscriber.
The coin-examining-apparatus consists of a receiver, a lever, a scale, a bar and the
draw-rod, which are brought into connection with certain levers in such a manner,
that the pulling of the draw-rod and thereby the opening of the apparatus can be
effected only by a coin of exact size and exact weight.
The device for the automatic calling, consists of a nose-arranged at the draw-rod
and of the double lever with a contact spring.
The automatic connection of the apparatus consists of a pin arranged on a lever
operated by a lever and contact-parts. The automatic ringing-off consists of a pin
arranged on a lever operating certain levers and a contact spring..
For the purpose of establishing the time of use and the automatic disengaging of
the connection and connecting to earth at the central station a shaft with levers is
moved by clock-mechanism with wheels and stopping-levers, and for stopping the
wheels springs with buttons are used.
Dated this 20th day of September 1889.
HERBERT & Co.
Agents to Applicant.
COMPLETE SPECIFICATION.
Improvements in Automatic Telephone Devices.
1, CARL GUST. HOFFMANN late of Leipzig, now of Louisen Ufer No. 44 Berlin in
the Empire of Germany. 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 a telephone apparatus with automatic action, which
can be placed at any suitable place in a similar manner as the known automatic
scales or sale apparatus and, on the introduction of a coin of predetermined value.
automatically establishes, without any attendance or supervision, the necessary
connections, and can be placed into relation with any urban or other telephone
establishment.
The improved device illustrated by the annexed drawing Sheets I to IV essentially

page_text: consists of the speaking apparatus, a mechanism for examining the coin, and
the box:
The box A contains in its lower portion the coin receiving device and the money
tester. Above these parts is provided a niche closed by two doors and enclosing the
speaking funnel of a microphone, while the two telephones for hearing are arranged
on the inside of said doors..
The coin examining apparatus, which is shown in Figs. 2 and 9 to 13 consists of
three brass plates a b c screwed together and so cut out as to leave sufficient space
for the deflection of a scale beam which is suspended in two pointed screws of the
bearing.c In a recess of the brass plates is provided a metal passage, the entrance
of which is adjustable in size by means of two steel tongues or plates g g', while
the whole passage can be raised and lowered by aid of two screws h and h¹. The
box is provided in its front side with a steel plate or a channel having such a
'cross section as to exactly admit of the introduction of a certain coin. Behind the
coin sloti a metal niece i¹ is provided, which is secured in the lever and has a
slanted portion. The plate c is fitted with a magnet bar . The plate bis so cut
out as to form two channels b' and be as shown in dotted lines by Eig. 9. The
channel b extends into a tube terminating above a slot of a round box l
Figs. 9. 12 and 13. The latter encloses, movable therein, a cylinder having at
one end an aperture 6. This cylinder is screwed to a rod carrying an adjusting
ring A second rod 1, lodged at and Fig. 13, carries a pin at its kneed
extremity and further an adjustable ring, a spiral spring a cone and a
handle projecting through the front side of the apparatus. Figs. 1 and 2. The
rod carries two pins, over which catches the fork of a two-armed lever k, which
transmits its movement to another two-armed lever Fig. 9.
The improved apparatus operates as follows:-
A proper coin introduced at the coin aperture i of the apparatus, runs over the
part and falls onto part, the plates a and c preventing the coin from lateral
deviation or from falling off. From part the coin passes to the scale beam d, and,
having arrived at the end d', lowers the same to a certain extent and, falling off. it
enters the passage f and arrives through channel be in the tube . The latter
encloses a spirally wound piece of sheet metal which so turns the coin as to cause
it to fall into slot of box . On the handle of rod being pulled, the pin F
enters into the box k, places itself against the coin, which covers the aperture of
cylinder and pushes coin, cylinder and rod forward Fig. 12. Thereby the
spring is compressed, the coin being placed over the aperture of box . The
displacing of rod also effects a movement of levers 7 and 8 about their
fulcrums 10. When the handle is released, the draw rod recedes by the
action of spring 1; the coin is thereby delivered of the pressure of pin and conse-
quently falls through the apertures and into the cash box C Fig. 2. Also the
rod with cylinder 3 and lever returns, by the adjusting ring labutting against
adjusting ring ko, into its normal position.
The movement of lever k thus produced aids in the operation of the apparatus in
the manner hereafter described.
A coin of too large a size cannot be placed into the receiving slot, whose measures
are so determined as to admit only coins of the maximal size equalling that of the
prescribed piece. A coin of too small a diameter will indeed pass through passage i.
but fall down when arrived on piece as it is not held or guided at the top by the
plates aand e, which are so shaped as to allow the proper coin only to be just guided
by its upper rim. A coin of excessive weight, when dropped in through slot i will
lower the scale beam. d too much at d' and consequently knock against the steel
plate gland be rejected by passing out through channel b' into the shell D Fig. 2.
A coin of inferior weight will not deflect the scale beam & sufficiently: consequently
knocks against the steel, plate g and likewise drops into the channel and passes
out at D Fig. 2. An iron disk of the dimensions of the coin of predetermined value
and therefore of approximately the same weight, will, when introduced be arrested
by the magnet bar a' while running over the scale beam d, thereby giving the latter

page_text: ་་
time to sink lower and causing the iron plate to abut against steel piece g¹ and arrive
through channel b₁ in the refusing shell.
Any angular objects introduced into the
down when handle is pulled, the lever
by the cone, whereby the parts
objects lose their support. The lever
of spring Fig. 10.
apparatus and lying on part i¹ or fall
being slightly turned about its fulcrum
are laterally displaced and the angular
resumes its inoperative position by the action
and
The rod can only move when a coin is in box kas only in this case the pin
of draw rod I meets with an obstacle connected with rod k. By the movement of
rod the contact between the two pieces nn. Fig. 11, is interrupted by means of
spring m attached to and insulated from rod and the contact piece'm is placed for
a short period into conductive communication with piece a' Fig. 12.
On rod being displaced, lever receives such movement that its upper arm
turns the two-armed lever o about fulcrum of Figs. 6, 7 and 8, thereby releasing the
lever p. The pivot of lever p is formed into a vertical shaft carrying at its other
end a lever p secured thereto the same as lover p and connected with spiral spring p.
Consequently, when lever p is released as mentioned above. lever which had
been held in the position: indicated by dotted lines in Fig. 4-yields to the action of
spring and assumes the position shown in plain lines Fig. 4;
+
The other extremity of lever p' is provided with a slot enclosing a pivot q² of the
door rails qq. The pivot q moves in a longitudinal slot q" of the box or casing
Figs. 2 and 4. in such a manner that, when fever precedes, the doors, revoluble
about gq are opened, Figs. 2 and 4.
The lever p has two pins p³ p the pin p' normally (when the doors are closed)
holds lever in such a position as to cause contact to be established between
springs sands. On the doors being opened, the lever s' is liberated from pin på
and depressed by the action of springs thereby arm is placed into contact with
springs and springs and recede from each other. Consequently the microphoné
is enclosed into the circuit and the speaking can commence.
By the opening of the door, the pin p has come into contact with the catch or
projection revoluble at the two-armed lever. Fig. 4, without therely affecting the
latter, as the catch r', which abuts against a pin r² of lever r. yields in this direction.
On the doors being closed, which is effected by pushing the same to by hand, lever s
is returned by pin p into its original position and contact is established
between sands. The pin 7 abuts against catch, which, moved in this direction;
forms a rigid piece with lever r. The latter presses lever against spring
thereby producing a short contact which effects the ringing-off at the central
telephone station.
The central station is provided for the public callers with a separate flat apparatus:
Figs. 16, 17 and 18, with polarised relay E. The armatures are normally held
by small spiral springs Fig. 18 in the midst between the pole shoes and are
provided with two small lateralmoses. These noses, as shown schematically
in Fig. 15, bold two flaps, one of which bears the number of the station! while the
other shows the word "ready" or equivalent indication. The central or exchange
station has moreover a strong clock mechanism (second-pendulum device) situated in
a casing, Figs. 20 to 23, which carries on consoles a box F. In flie latter revolyes
by the clock mechanism a shaft G at a speed of precisely 5 minutes to a revolution:
Figs. 22 to 26. This shaft carries for each public speaking station a lever Hand a
wheel J placed loose on shaft G and rigidly connected by a spiral spring with a
lever H rigidly secured on G. This lever therefore moves in 5 minutes once about
its shaft and normally takes along the wheel J Fig. 24. When however 'button'P is
depressed. spring O moves downward and turns the two-armed; deyer, N. about its
fufcrum. Thereby lever M is released and falls down into the teeth of of wheel J;
which consequently becomes unable to follow the movement of lever H. The latter
now moves alone. Fig. 25. until it abuts after 5 minutes against pin L of wheel J
and takes this wheel along by lever M being pressed out of the teeth of and
arrested again by lever N. These parts are provided for each public speaking

page_text: station, the casing, Fig. 21 being supposed to be adapted for 12 stations. The devise
has for its purpose to establish contact at S by pressing the knob P in order to ring
for the ordinary subscriber who is desired to be spoken to and to simultaneously
establish earth connection at Q for clearing the connection to the subscriber. After
the lapse of five minutes, this contact is automatically re-established, that is to say,
conduit is placed to earth at the central station, thereby excluding the public speaking
station. If further communication is desired, the doors must be closed and another
coin is required to be placed into the receiving slot. If the ringing off takes
place prior to the lapse of five minutes, the official can draw back the lever M by
pulling the knob R by hand. The whole exchange device is schematically represented
by Figs. 14 and 15.
The conduit when inoperative is connected with the earth. On the knob 1 of the
automatic public station being pulled, contact is established at n n'. A positive
current passes from battery B' through lightning conductor 2 and conduit 3 to
the central station, hence to the lightning conductor 4, polarized relay E. spring 0,
and, no interruption being effected, through contact 5 and 6 to the earth plate 19 and
back to earth plate 1 and to contact n n to the battery.
The armature of the polarized relay E is drawn to the right and the flap with the
number of the station falls down. The official plugs by nieaus of plug 18 Fig. 19
and thus inserts his telephone. After he has asked and learned which subscriber is
desired to be called, he uses the plugs 9 and 17, thereby placing the public station
into communication with the subscriber. Subsequently he presses on the respective
button P', thus stopping by leyer M. the wheel J and disestablishing at Q the earth
connection. The speaking can now commence, as also at the public station, the
microphone is engaged by lever s being in contact with s. The telephone is fed by
the Meiding battery M': the connection in the speaking position is as follows:-
Earth spring n. telephone, induction coil, spring . lightning conductor 2;
Gonduit, central station, lightning conductor 4, relay E, spring O. spring 5,
plug 9 Fig. 15, plug 17 tube L1, spring 10 lightning conductor 15, conduit 16 to the
earth plate of the subscriber. On the closing of the doors of the public speaking
station the paris give contact and a current is sent through the conduit which
current is opposed to that for calling. From the positive pole of the battery B' the
current passes through parts s'giving again contact, and spring n to the earth,
subscribers conduit. 16, central station, lightning conductor 15, spring 10, tube 11,
plug 17, plug 9, spring 5, contact. S. relay E. lightning conductor 4, conduit 3,
lightning conductor 2. contact, and negative pole of battery B. The armature
of relay. E is, thereby drawn to the left and the flap with the word "ready" or
equivalent indication falls down. Subsequently the official, unless this has been done
already automatically, establishes earth connection at Q by pulling the respective
knob R and releases wheel J from lever M.
On the Kunb P being pressed down, the contact S is closed and the respective
subscriber called, by a current circulating from battery B, contact. S. plugs 9 and 17.
ube spring.10. lightning conductor 15, conduit 16. subscriber's earth and
battery B. The relay 14 of the subscriber is, during this period. as also during
speaking, excluded. By a simple mechanical device which can be attached to spring o
and actuates a counting mechanism, it is possible to allow the number of operations
of the speaking station, which must correspond with the number of coins enclosed in
the money box, to be at any time ascertained.
Instead of using this counting mechanism, the money box of the public telephone
station may also be closed by a leaden seal. the coin slot being in this case so shaped
as to preclude any shaking out of the money.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed, I declare that what I claim is:-
In an automatic public telephone station
The combination of a telephone system with a coin examining apparatus, and a
clock mechanism situated at the central station, in such a manner as to cause, by the

page_text: or a certam coin into the apparatus, a draw rod to be placed into
connection with a lever device, which, on the handle or knob of the draw rod being
pulled, liberates the telephones, and a call being automatically effected to the central
station. which establishes the desired connection with the insertion of a clock
mechanism, which after a certain time automatically suspends by a lever device,
the connection with the automatic telephone station, substantially as set forth.
2. A device for effecting an automatic call to the central station, consisting of
spring mattached to rod K and the contact pieces n. and n² substantiallyas set forth
3. A device for automatically inserting the apparatus consisting of a pin p
attached to lever p', levers and contact parts substantially as set forth.
4. A device for automatical ringing off, consisting of pin secured on lever p'.
levers with part lever and contact spring substantially as and for the
purpose set forth.
5. A coin examining mechanism consisting of a scale beam d over which rolls
the coin and which thereby sinks so far at its extremity d' as to cause a proper coin
to pass into a channel, while too heavy or too light coins abut against the upper or
lower rim of the aperture of channel and pass through channel b' out of the
apparatus. in combination with the movable parts and the tube K, cylinder K³.
levers and rod and draw rod with handle 1, substantially as set forth.
6. A clock mechanism to be placed at the central station and serving for indicating
the time during which the apparatus has been used. and for automatically suspending
in established connection and inserting the earth, said clock mechanism being
characterized by a shaft G. moved by the same. in combination with levers H,
wheels J. click levers N M and springs O serving for arresting the wheels,
ubstantially as set forth.
Dated this 10th 1..1..