Improvements in and relating to Electric Call Apparatus.
Year: 1891

page_text: Date of Application, 9th May, 1891
Complete Specification Left, 9th Mar., 1892-Accepted, 30th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electric Call Apparatus.
I GRAYDON POORE of 35 Oak Hill Road, Putney in the County of Surrey,
Civil Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to certain improvements in and relating to that class of
call
or signalling apparatus in which any given or predetermined signal is
electrically transmitted from one place (say a calling station) to another (say a
central station) on operation of the apparatus, and has for its object to enable such
apparatus to be more conveniently utilized and adapted to the public or a message
service than heretofore.
According to my improvements I apply to an electric call or signal transmitting
apparatus a coin operated mechanism, and I so arrange the interual parts that
upon the insertion of a coin or token a part is released and the operator is enabled
to pull out a drawer or equivalent device which may bear or contain one of a
number of cards, writing materials, or other thing or things applicable to the
purpose intended, and contained in the apparatus; this action serves to store up
sufficient power by spring, weight, or equivalent action to actuate the transmitting
mechanism when required, and the same action should the line be clear also serves
to release the power storage mechanism and so operates the transmitter and
despatches the signal.
If however the line is engaged at the time of the operation the power storage
mechanism is not at once released but retained and delayed by suitable selfacting
mechanism until the line is clear, thereby preventing the possibility of more than
one signal being transmitted through the single wire at one time, and this fact may
be indicated by the closing of the money slot until the previous message has been
despatched. The delay may be effected by means of the cutting in or out of circuit
of an electro-magnet the armature of which acting on a catch or other suitable
interposed mechanism controls the action of the said power storage mechanism, and
is connected to and regulated by suitable timing mechanisms.
In the case of a system of such apparatus in any district on one circuit, if a
signal is being transmitted from any instrument and at the same time power to
signal has been stored up in any other or others the timing apparatus are so set that
each will send its signal in turn and no two simultaneously, and on any second
signal being sent all the timing mechanisms are restarted.
In case of the electric current available being but small relays may be inserted
in connection with the electro magnets in the known manner.
The apparatus is provided with an inner receptacle for written messages and
also an internal switch or transmitter not accessible to the public but by which the
messenger answering the call on opening the apparatus can also transmit a call or
calls to the central station, or by which, assuming the line is engaged, he can store
up power for that purpose by suitable mechanical means.
Instead of storing up power by the action of the operator as described the same
may be effected by means of previously wound clockwork, or by an electro motor
contained in the apparatus worked from the central station with which the instru-
ments are in communication, such stored power being released or allowed to be
released by the coin action.
Dated Oth day of May 1801
J. C. CHAPMAN,
Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Electric Call Apparatus.
I, GRAYDON POORE of 35 Oak Hill Road, Putney, in the County of Surrey,
Civil Engineer 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 and relating to that class of
call or signalling apparatus in which any given or predetermined signal is
electrically transmitted from one place (say a calling station) to another (say a
central station) on operation of the apparatus, and has for its object to enable
such apparatus to be more conveniently utilized. and adapted to the public or a
message service than heretofore.
According to my improvements I apply to an electric call or signal transmitting
apparatus a coin operated mechanism, and I so arrange the internal parts that
upon the insertion of a coin or token a part is released and the operator is enabled
to pull out a drawer or equivalent device which may bear or contain one of a
number of cards, writing materials, or other thing or things applicable for the
purpose intended, and contained in the apparatus; this action serves to store up
sufficient power by spring, weight, or equivalent action to actuate the transmitting
mechanism when required, and the same action, should the line be clear, also serves
to release the power storage mechanism and so operates the transmitter and
despatches the signal.
If however the line is engaged at the time of the operation the power storage
mechanism is not at once released but retained and delayed by suitable self-acting
mechanism until the line is clear, thereby preventing the possibility of more than one
signal being transmitted through the single wire at one time, and this fact may be
indicated by the closing of the money slot until the previous message has been
despatched, or otherwise. The delay may be effected by means of the cutting in or
out of circuit of an electro-magnet the armature of which acting on a catch or other
suitable interposed mechanism controls the action of the said power storage
mechanism, and is connected to and regulated by suitable timing mechanism.
In the case of a system of such apparatus in any district on one circuit, if a
signal is being transmitted from any instrument and at the same time power to
signal has been stored up in any other or others, the timing apparatus are so set
that each will send its signal in turn and no two simultaneously, and on any
second signal being sent all the timing mechanisms are restarted.
In case of the electric current available being but small relays may be inserted
in connection with the electro magnets in the known manner.
The apparatus is provided with an inner receptacle for written messages and
also an internal switch or transmitter not accessible to the public, but by which
the messenger answering the call on opening the apparatus can also transmit a call
or calls to the central station, or by which, assuming the line is engaged, he can
store up power for that purpose by suitable mechanical means.
Instead of storing up power by the action of the operator as described the same
may be effected by means of previously wound clockwork, or by an electro-motor
contained in the apparatus worked from the central station with which the instru-
ments are in communication, such stored power being released or allowed to be
released by the coin action.
I will now describe my invention in reference to the accompanying drawings in
which
Figure 1 is a plan of the machine taken below the coin-freed locking gear.
Figures 2 and 2 are together a sectional elevation of left side.
Figure 3 is a sectional elevation of right side showing the slide withdrawn and
power stored, and also the messengers private call apparatus.

page_text: Figure is a detail or messenger can apparatus.
Figures 8 and 9 are sections showing key ways for same hereinafter explained.
Figure 10 is an elevation of key, and
Figure 11 a section on line 1-2 thereof.
Figure 12 is a detail of foot of switch levers.
In all these figures similar letters refer to similar parts.
The whole of the hereinafter described mechanisms and goods are enclosed in
suitable casings, ordinary and convenient provisions being made for locking, writing,
giving directions, and so forth, which are sufficiently indicated in the drawings with-
out letters of reference.
To simplify the description of the invention I have divided it into four main
parts, iz. 1st. the coinfreed locking and operating mechanism. 2nd. the electric
call and transmitting or telegraph gear. 3rd. the timing gear; and 4th. the
additional messengers private call apparatus.
First in regard to the coin-freed locking gear and operating mechanism. Any
predetermined coin, token, or equivalent (hereinafter called the coin") may be
used, and the gear may be of any suitable type and in itself forms no part of my
present invention. As illustrated in Figures 2, 24, 3, and 4. A is a slide carrying
writing materials stored in a casing above it, and having a suitable handle A°. On
the lower part of A at the front end are centred two downwardly-projecting pawls a
connected by a cross bar a¹ having a projection aº and the said pawls are normally
held geared with twin racks a² a by a spring a8; A¹ is the coin slot so arranged
that when a coin X, Figure 4, is inserted and the slide A pulled out, the said coin
engaging the projection a will lift the pawls clear of the racks so that the slide A
is free to be pulled out, thereby delivering the lowest packet of the writing
materials. One pawl a, Figs. 3 and 4, has a tail a³ with a lateral pin a which when
the pawls are lifted and the slide pulled out is depressed and engages back rack a*
so as to prevent the slide being pushed back without having been first fully pulled
out, and it also prevents the pawls re-engaging the racks a² during the outward
stroke; after the projection aº has cleared the coin the latter is free to fall into any
suitable receptacle. On the return of slide the pin aº of tail a³ runs above the inverted
rack and so clears its teeth. A³ is a depending arm fixed to slide A, carrying at its
foot a spring-pressed tappet arm which operates the telegraph mechanism during
its forward travel, but is inoperative on its return travel.
Secondly, in regard to the electric call and transmitting or telegraph gear.
The type of instrument illustrated is one in which constant currents are employed
and which works in a closed circuit; the call is given by interruption of the current
produced by breaks in the circuit; these breaks are caused during the revolution
of a contact wheel D (hereinafter called the "call wheel ") which consists of an
insulated drum D having three electrically connected metallic rings D', D², D³ let
into its periphery. Ring D' is plain and rubs against a fixed contact C in the main
circuit. Ring 12 has notches d the characteristics of which constitute the prede-
termined and identifying signal and serve to break the current passing through
contact. C to a second and moveable contact switch C' also in the circuit. The
ring D³ has notches of different characteristics from those on ring D, and its use
is hereinafter described in reference to the private messengers call. The call
wheel D is carried upon spindle D mounted in bearings in standards S. To
transmit the predetermined signal the call wheel D must perform one complete
revolution and to regulate and easily control the speed thereof-as and for a
purpose hereinafter described in reference to timing gear-a train of wheels B', B³,
and a fly B3 are provided and suitably mounted.
The fly is driven by a pawl B, Figure 2, to prevent sudden shock when the call
wheel D has completed a revolution and transmitted the signal. Upon spindle D₁
is a loose pinion gearing with a quadrant Q and free to revolve during its forward

page_text: stroke said pinion is fast to ratchet wheel g' which gears during the backward
stroke of the quadrant with a pawl qupon a disc D' fast on spindle D', as separately
shown in Fig. 6, so that it will thus drive the call wheel D through its required
revolution.
The quadrant Qis centred on the end of main spindle S carried in bearings in
suitable standards S above which point is centred upon it on a pin ¹ a tumbler F
hereinafter fully described.
From the same pin w by a cord w passing over a suitable guide pulley is
suspended the main driving weight W which is raised during the forward stroke of
the quadrant Q by the power applied on withdrawal of slide A, and which retracts
the said quadrant by its fall, then as explained revolving the call wheel D; the
single revolution of this is determined by stop d' affixed thereto engaging projec-
tion on a lever L mounted on an oscillating shaft running transversely across
the machine.
To raise the said lever L in time to cause projection 12 to come to come in the
travel of stop d' a lever L'is so fixed upon the shaft as to engage a pin q³ upon face
of quadrant Q at the end of its back stroke and thus serve to oscillate the shaft /
and raise lever L.
The lever L is depressed in time to free to stop d' by means of the counter
weight when on return stroke of quadrant the pin q3 is removed.
To prevent tampering with the apparatus during the transmission of a call the
following arrangement of mechanisms are employed.
זי
The tumbler F carries a pin on its face which is the main operating pin and is
extended into the line of travel of the tappet a. The oscillation of F is limited in
a forward direction by engaging a stop q on quadrant Q and in a backward
direction by engaging spindle S or a boss thereupon: a pin on back of F serves
to replace in its forward position by engaging, during the latter part of its back
stroke, stop on standard S°; the back pin is acted upon by fixed spring f³
constantly forcing F backwards, all as hereinafter explained.
Thirdly, in regard to the timing gear; the object of this is to prevent (where a
number of apparatus are used in one electric circuit) any machine interfering with
the line or any other machine when in action, until such action is completed, and
the line again clear: also to provide that when the line is so cleared after any
single action, each machine shall in turn be free to send its call (if any has
been stored in it by an operator) and no two shall be so freed and operative
simultaneously.
To effect this it is necessary that the pulling out of any one slide shall imme-
diately prevent that machine and every machine from working for a given period of
time, and that such periods of time shall be different in every machine on the
same circuit, so that the machine which is set for the shortest period of retardation
will first be free to act, and then each other one will be automatically released and
rendered operative in turn, according to its prearranged period of retardation, and
will on the transmission of the call render operative all other machines again
in turn.
The timing gear illustrated is as follows:-On the same spindle S as the afore-
said quadrant is fixed a switch lever T having at its foot a tappet arm t adapted
to depress a spring contact E placed in the circuit during the forward motion of
the quadrant and so break the circuit, and on its return to ride inoperatively
over the said contact E. G is a weighted brake applied to the fly B³ for the
purpose of preventing the raised weight W from falling and so store its power. To
remove this brake at the proper times, a timing lever H is provided having
a counter weight H' for lifting it and a dashpot for regulating its speed of
ascent the dashpot is of the well known "pump" type so that it will quickly fall
but its ascent is retarded. For depressing the lever H in order to apply the brake,
a weight is provided and suitably connected to the armature m of an electric
magnet M in the main circuit which is attracted when a current is passing. To
prevent the descent of the timing lever H (and the consequent action of brake G

page_text: during transmission of a call), a projecting arm ³ is fixed on H, and upon the
spindle D is mounted a flat disc V having a slot v in the periphery: the arm ³
riding upon the periphery of V holds up H, until return of the slot, when h³
will pass down and allow the timing lever H to fall. While the brake is on, a bye-
pass is or may be provided for the current, so that in case of the connections being
broken by the depression of the contact E in any other machine the circuit cannot
be broken. This byepass remains operative while the timing levers in all the
machines are in depressed positions, but as soon as they resume normal upward
positions the byepass is cut out.
Fourthly, in regard to the additional messenger's private call apparatus. This is
for the purpose of permitting the messenger (on his arrival in answer to a public or
operator's call) to send to the central or receiving station a distinctive call, for
example, that a second messenger is required when two messages are in the
receptacle, and such private call is distinct from the public call. For this purpose
the ring D² is provided on call wheel D having differently arranged spaces or
notches d² d on its periphery serving to distinguish it from ring D³ and to identify
the machine, and the contact switch C' is arranged to be moved across transversely
between the public call ring D³ and the said private call ring D²---
2-a suitable plate
connecting these two at the point where the contact C¹ travels across the same, so
that the electric circuit shall not be broken during the operation. The cross move-
ment of C¹ is effected by the vibrating lever R and sliding bar R' illustrated in
Figs. 1, 2, 3, and 4.
The messenger carries a key K of the form shown in Figs. 10 and 11, having a
feather k for the purpose of enabling him to wind up the weight W and store power
in the machine for subsequent use.
The key hole s passes through three independent parts before reaching and acting
on the main winding spindle S. These three parts are, an exterior boss S' mounted
upon a standard Se and provided with two key ways s', 2nd. a loose ratchet wheel S2
in whose boss, Fig. 8, are 4 key ways s²; and 3rd. a boss S³ mounted upon, but not
fixed to the end of the winding spindle S with one internal key way, Fig. 7, and
having two external laterally projecting arms. One of these so carries a stop s
which passes through a slot, see Fig. 7, in the other so that the first s can have
some travel before operating the other which serves to drive the winding
spindle S, the travel being limited by the stop piece 8.
The ratchet S2 is geared with a pawls to prevent back action: upon the boss S³
is a finger y which, when turned, at once depresses a spring return bar y causing
its foot to gear to with a slot r in the sliding contact bar R', see Fig. 12, and move
same for the purpose of throwing the switch C' from the public to the private
ring of the call wheel D. The parts when operated take the position dotted
in Fig. 7.
To prevent the messenger inserting his key when a message is already stored by
a public operator, a rod Z connected to cross spindle aforesaid by means of a
short lever z passes through a hole in the boss S³, and when the weight W is lifted
for the purpose of sending a public call the rod Z projects across the keyhole s
and so prevents the insertion of the key, as illustrated in Fig. 3, but when no power
is stored by W Z is withdrawn and the hole is clear.
In describing the operation of a number of machines such as are above described
but all with distinctive call wheels, and all in the same electric circuit, assuming
the line is clear and the circuit consequently closed, a current will be flowing round
the circuit and all the electro magnets M will be made and their armatures
attracted. This will hold up all the weights and all the timing levers H will
be in their upward position and the brakes G off.
Then after the insertion of a coin and the freeing of the locking mechanism as
hereinabove described, the first part of the outward stroke of slide A through
tappet a and the tumbler F turns Q and spindle S causing lever T to depress the
switch E and instantly break the circuit, so that the electro-magnets M in all the
machines release their armatures and apply the brakes G.

page_text: The further motion of the slide A clears lever T from spring switch E which
then re-closes the circuit allowing all magnets to again attract and lift their
armatures, and the balance weights H' then slowly raise the timing levers H and
take off the brakes, not simultaneously, but each one successively in turn,
according to the prearranged periods of retardation as effected by the dashpots
described.
The further pull of the slide fully lifts the weight and disengages tappet a³ from
pin of tumbler F. The pin y³ has during the travel of Q been withdrawn from
lever L' so that the counterweight 13 will depress lever L and remove projection /
hitherto by stop locking the call wheel D which is then free to revolve and
transmit its message if the line is clear, and the brake G lifted as described. When
weight W falls it retracts tumbler Funtil pin f' thereon engages stop; the
further pull of the falling weight then causes F to revolve in a forward direction
on its own centre w until its front edge engages stop 7 on quadrant Q, at which
time the operating pin will be in the line of travel of the tappet a' so that when
the slide is again pulled out it will force forward F and through stop 5 actuate also
the quadrant Q, and at the same time lift the weight W again and store power.
When the slide has again been withdrawn, after a certain travel tappet a' will ride
over and cease to engage pin f, and spring acting on pin f2 will then force back
tumbler F to its full backward position, and so move the pin out of line of
the tappet a-thus the slide may be left in any intermediate position without
liability to be operated again until the weight has fallen and transmitted the call;
but if the line is engaged and the brakes applied then the power stored by W is
retained until the line is free. When the wheel D begins to revolve, the disc V
on the same spindle revolving under 3 on lever H holds up the timing lever Hand
so prevents the interruption of the current (caused by the message) acting to apply
the brake to the machine in action, while allowing same to be applied in all other
machines. On revolution of D after the last notch 3 has passed the fixed contact C
the circuit is again closed and the brakes successively released in each machine.
If in the meantime any machine has been used and so has its weight lifted it will
despatch its call as soon as its turn comes and its brake is released-the break in
the current due to the message will once more cause the brake to be applied to all
except the machine in action.
It will thus be seen that the first action is to open the circuit which applies the
brakes to every machine (including the one in use) and so prevents any operation
until the laps of a time varying in each machine as set forth; and then each
machine in turn is free to act if its weight is lifted, but the moment any one starts
it relocks all the others and at the completion of its operation each in turn is again
freed. On arrival of a messenger he can lift the weight by his special key (if he
desires to call the receiving office) instead of by operating the slide, this moves
the switch (from the public call 13 to the private call D', the operation otherwise
being the same as above described for the public call.
As above stated the machines described are intended for use on a closed circuit
and a constant current, but I wish it to be understood that I do not limit myself
to this as it is obvious that the same result can be attained by providing a battery
in each machine and arranging the transmitting mechanism to cut the said battery
in and out at each operation. I have set forth under each of the four main heads
above stated one type or set of each mechanism required to effect the combined
purposes, but I wish it to be understood that the mechanisms are only typical and
may obviously be varied and modified to effect the same ends-therefore I do not
confine my invention to any specific arrangements of apparatus for performing
same, and
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. In coinfreed electric call apparatus for use with others in one electric circuit,

page_text: an arrangement of mechanisms whereby on the operation of any one machine the
condition of the circuit is at once changed, so as to lock all the machines and
prevent the action of any of them (including the one operated) until after the lapse
of pre-arranged periods of time, such periods being varied for each machine by
means of differently timed dashpots as described, or otherwise, and so that each
machine will in its turn be freed and in a condition to transmit its call if
required.
2. In a coinfreed electric call apparatus for use with others in one electrical
circuit, means such as are herein above described whereby each machine will retard
and transmit in its turn a predetermined call, and no two machines simultaneously,
consisting in the use of a moving part such as lever H controlled by a counter-
weight Hand dashpot h or equivalent, and adapted to restrain the power stored
as specified for a pre-arranged period through a brake G acting on a train of
wheels. or equivalent medium, and to liberate same by the action of electro-
magnets Mon armature connected to and acting on said moving part H,
substantially as set forth.
3. The means of determining the one exact revolution of the call wheel D
described (or the required motion of an equivalent call device) consisting of a stop
such as normally locking same but automatically removed just before the
commencement of the motion so as to leave the part free to move, and replaced in
time to arrest it at the completion of its required motion, substantially as se
forth.
4. An arrangement of mechanism such as is described in reference to tappet on
slide A, tumbler F, quadrant Q and their mountings, and weight W, for operating
the transmitting mechanism and storing power by the outward movement of a slide,
whereby the slide may be left in any intermediate position (after having stored
the power) without interfering with the return to normal position of the transmitting
mechanism, substantially as set forth.
5. Means such as are exemplified by the arm ³ and slotted disc V moving with
the call wheel or equivalent as above described, for holding up the timing lever or
device during transmission of a call and preventing the application of the brake
device in the acting machine while at the same time allowing the application of the
brakes in all other machines in the same electric circuit.
6. The use in conjunction with coinfreed electric call apparatus such as is herein-
before described of an arrangement whereby a messenger can transmit a private
call to the receiving station, or store power for that purpose substantially as
set forth.
7. In a coinfreed electric call apparatus the construction and arrangement of
supplemental mechanism hereinabove described for a messenger's private call
consisting in the separate ring D on call wheel D, moveable switch C', its
connections, and the key operated device; all substantially as set forth.
8. The hereinabove means of preventing the insertion of the messengers
private key except at the proper time, consisting of levers Z z cross spindle
and connections operating substantially at the times and in the manner
set forth.
9. The cointreed electric call apparatus with timing gear and private messenger's
call constructed arranged and operating, substantially as hereinabove described
and illustrated in the drawings.