Improvements in Electric Call and Alarm Apparatus.
Year: 1895

page_text: Date of Application, 3rd Jan., 1895
Complete Specification Left, 1st Oct., 1895-Accepted, 2nd Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in Electric Call and Alarm Apparatus.
We, ERNST HERZ of St. Johann-Saarbrücken in the Empire of Germany, and
JEAN PIERRE HARTFUSS, of Merzig, in the Empire of Germany, Manufacturers,
do hereby declare the nature of this invention to be as follows:-
This invention relates to the transmission of calls and alarms from a central
station or place either automatically at predetermined time or times for each
individual place at which the call or alarm is to be given, or at any moment to the
whole of the places in connection with the central station or place. The apparatus
is also intended to permit the attendant at the said central station or place to
receive a signal wherefrom it may be understood that the call or alarm has been
noticed at the placed called.
The improved apparatus hereinafter described is especially suitable for use in
hotels and enables the occupant of any room to arrange for receiving at any time
he may desire a call or alarm which by the setting of mechanism in the hotel office
or other central place, will be automatically set in motion when the desired time
arrives and continue in action until by a special movement of the occupant in said
room it is made to cease, whereupon the attendant in the office will be notified
automatically by a signal that the call has been effectual.
The apparatus also enables a simultaneous call to be made in every room, when
so operated by the attendant for this purpose for instance to give an alarmn in case
of fire.
The nature of the apparatus is as follows;-
-Within a suitable frame or casing at
the cental place is a plurality of dials resembling clock-faces and having indicators
similar to clock hands. Each of these dials corresponds to a particular room in
the hotel or other particular place and the mechanism governed by the indicators
is in electrical connection with a signal device such as an ordinary electric bell in
the respective room. The indicators may be set by hand to point to any desired
time when the call is to be next transmitted to the particular chamber.
With this indicating device and its mechanisms is combined a clock which may
govern the whole or any desired number of such mechanisms. This clock moves a
frame which may be made up of a number of parallel rods guided by cranks or
otherwise so that its movement is a rotary one, while maintaining the parallelism
and orientation of its parts. Thus every point of this frame performs an equal
similar and synchronous movement and according to the position of the mechanism
governed by the respective indicators the said frame will at the time indicated by
the said indicators cause a contact to be made with reference to the mechanism of
each said indicator that will set in action a current that will cause the signal
relating to that indicator to be set in operation.
The contact may be made by the frame or pins thereon coming in contact with
adjustable contact arms connected severally through commutators or contact making
and breaking devices to the respective places where the calls are to be made.
Between the contact arm and the signals there may be a device comprising a
rocking lever provided with an automatic commutator and retainable in such a way
by a stop fixed on the armature of an electro-magnet that when the indicator is
adjusted by means of a key, the said rocking lever which carries a signal disk is
pushed into the position of arrest thus hiding the signal disk, whereby also the
corresponding signal bell in the place to be called is placed in circuit to be operated

page_text: i
when the circuit is completed by the meeting of the frame or its pin and the
contact arm aforesaid, and until. by a particular act of the person called at the
place where the call is given there is produced a release of the rocking or signal
lever, whereupon the signalling bell of that place is put out of circuit and the
visible signal given that the call has been noticed.
In view of the fact that the electro-magnets of the commutator and of the signal
lever retaining stop will preferably be placed in series in the same circuit, it is
necessary to provide the signal device with an arrangement to prevent interruption
of the circuit when the armature spring of the bell hammer at the place of call
leaves its contact. For this purpose a second spring is provided on' said armature
to enter into contact when the aforesaid contact is broken and so connect a return
or shunt current which will prevent the release of the armature of the commutator
and signal lever stop until by a special device at the place called and to be operated
by the person called, this return or shunt circuit is also broken and the signal lever
thus released, moving the commutator with it and putting the bell at the place
called out of circuit until the apparatus is again set to transmit a call.
To permit signals to be transmitted to all stations at the same time and also to
give to such signals a distinctive character from those of the ordinary calls, the
aforesaid rotary frame governed by the clockwork may be made so that it can be
shifted into a parallel plane or otherwise so as to make contact with a number of
plates or contact springs and. so complete circuits with all the various stations or
places to be alarmed; the clockwork may also be arranged so that by a movement
of disengagement of the usual wheel train or otherwise, the said frame which
normally moves at a slow rate, synchronously with the hour hand of the clock, may
be made to move rapidly so as to produce a rapid make and break of all the
circuits, thus causing the signal bells to give periodically interrupted signals which
will be more effective as alarms. The shifting of the rotary frame may be
performed through the operation of rotary cams, of the nature of sectors with
inclined planes thereon, operating to move the gudgeons of the cranks carrying
said frame. Said cams being all connected by levers and rods for simultaneous
movement from one hand-lever, which may also be combined with the device
necessary to accelerate the movement of the clockwork. The frame carries. pins
to come in contact with the contact arms and to cause the contact to operate
exactly at the moment desired; the ends of the contact arms may be of roof or
curved form having on one side or towards one edge an insulating cover piece and
a free metal surface on the other side or towards the other edge.
The rocking or signal lever carries a disk which is visible through a window or
aperture in the dial or near the same when the lever has fallen from its detent, but
is invisible when the lever is held up by said detent. On the gudgeon or hub of
this lever is a helicoidally grooved drum in the groove of which a nose on a spring
or spring-pressed lever engages.
When a key is inserted to adjust the angular position of the contact arm so that
the clock-driven frame may come in contact therewith at the desired time, the said
key displaces the spring or spring-pressed lever causing its nose to move in the
helicoidal groove aforesaid and rotate the drum and with it the signal lever until
the latter is caught behind its detent. On the said drum is a contact which is by
rotation of the drum brought into contact with a contact spring thus setting the
respective station to be called in circuit with the contact arm and the clock-driven
frame.
The detent may have a double escapement the first detaining hook releasing the
lever when the armature governing the detent is attracted by passage of a current,
and the second hook receiving it until the passage of current ceases and the said
armature falls back again from its electro-magnet.
Dated this 3rd day of January 1895.
HERBERT HADDAN & Co.,
Agents to the Applicants.

page_text: Improvements in Electric Call and Alarm Apparatus.
. We ERNST HERZ of St. Johann Saarbrücken in the Empire of Germany and
JEAN PIERRE HARTFUSS, of Merzig in the Empire of Germany, Manufacturers
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 the transmission of calls and alarms from a central
station or place either automatically at a predetermined time or times for each
individual place at which the call or alarm is to be given or by personal action at
any moment to the whole of the places in connection with the central station or
place for instance, upon emergency. The apparatus is also intended to permit
the attendant at the said central station or place to receive a signal wherefrom
it may be understood that the call or alarm has been noticed at the place
called.
1
The improved apparatus hereinafter described is especially suitable for use in
hotels and enables the occupant of any room to arrange for automatically receiving
at any time he may desire a call or alarm by the setting of mechanism in the hotel
office or other central place so that said signalling apparatus will be automatically
set in motion when the desired time arrives and continue in actiou until by a special
movement of the occupant in said. room it is made to cease whereupon the attendant:
in the office will be notified automatically by a signal that the call has been
effectual.
The apparatus also enables a simultaneous call to be made in every room, when
so operated by the attendant for this purpose, for instance to give an alarm in case
of fire..
The nature of the apparatus is as follows:-Within a suitable frame or casing at
the central place is a plurality of dials resembling clock faces and having indicators
similar to clock hands. Each of these dials corresponds to a particular room in
the hotel or other particular place and the mechanism governed by the indicators
is in electrical connection with a signal device such as an ordinary electric bell or
one set in action by a spring work or the like in the respective room.
indicators may be set by hand to point to any desired time when the call is to be
next transmitted to the particular chamber.
The
With this indicating device and its mechanisms is combined a clock which may
govern the whole or any desired number of such mechanisms. This clock moves a
frame which may be made up of a number of parallel rods guided by cranks or
otherwise so that its movement is a rotary one while maintaining the parallelism
and orientation of its parts. Thus every point of this frame performs an equal,
similar and synchronous movement and according to the position of the mechanism
governed by the respective indicators the said frame will at the time indicated by
the said indicators cause a contact to be made with reference to the mechanism of
each said indicator that will set in action a current that will cause the signal
relating to that indicator to be set in operation.
contact
The contact may be made by the frame or pins thereon coming in contact with
adjustable contact arms connected severally through commutators or
making and breaking devices to the respective places where the calls are to be
made. Between the contact arm and the signals there may be a device comprising
a rocking lever provided with an automatic commutator and retainable in such a
way by a stop fixed on the armature of an electromagnet that when the indicator
is adjusted by means of a key, the said rocking lever which carries a signal disk is
pushed into its position of arrest thus hiding the signal disk whereby also the

page_text: corresponding signalling bell in the place to be called is placed in circuit when the
circuit is completed by the meeting of the frame or its pin and the contact arm
aforesaid and until by a particular act of the person called at the place where the
call is given there is produced a release of the rocking or signal lever, whereupon
the signalling bell of that place is put out of circuit and the visible signal given
that the call has been noticed.
When an electrically operated signal bell is used, in view of the fact that the
electromagnets of the commutator and of the signal lever retaining stop will
preferably be placed in series in the same circuit, it is necessary to provide the
signal device with an arrangement to prevent interruption of the circuit when the
armature spring of the bell hammer at the place of call leaves its contact. For
this purpose a second spring is provided on said armature to enter into contact
when the aforesaid contact is broken, and so connect a return or shunt current
which will prevent the release of the armature of the commutator and signal lever
stop until by a special device at the place called and to be operated by the person
called, this return or shunt circuit is also broken and the signal lever thus released,
moving the commutator with it and putting the bell at the place called out of
circuit until the apparatus is again set to transmit a call.
To permit signals to be transmitted to all stations at the same time and also
to give to such signals a distinctive character from those of the ordinary calls, the
aforesaid rotary frame governed by the clockwork may be made so that it can be
shifted into a parallel plane or an arm may be brought into such position so as to
make contact with a number of plates, contact springs or keys, and so complete
circuits with all the various stations or places to be alarmed; the clockwork may
also be arranged so that by a movement of disengagement of the usual wheel train
or otherwise, the said frame which normally moves at a slow rate synchronously
with the hour hand of the clock, may be made to move rapidly so as to produce a
rapid make and break of all the circuits, thus causing the signal bells to give
periodically interrupted signals which will be more effective as alarms. The
shifting of the rotary frame when that method is desired may be performed through
the operation of rotary cams, of the nature of sectors with inclined planes thereon,
operating to move the gudgeons of the cranks carrying said frame. Said cams
being all connected by levers and rods for simultaneous movement from one
hand lever, which may also be combined with the device necessary to accelerate
the movement of the clockwork.
The frame carries pins to come in contact with the contact arms and to cause
the contact to operate exactly at the movement desired; the ends of the contact
arms may be of roof or curved form having on one side or towards one edge
an insulating cover piece and a free metal surface on the other side or towards the
other edge.
The rocking or signal lever carries a disk which is visible through a window or
aperture in the dial or near the same when the lever has fallen from its detent,
but is invisible when the lever is held up by said detent. On the gudgeon or hub
of this lever is a helicoidally grooved drum in the groove of which a nose on a
spring or spring pressed lever engages.
When a key is inserted to adjust the angular position of the contact arm so that
the clock driven frame may come in contact therewith at the desired time, the said
key displaces the spring or spring pressed lever causing its nose to move in the
helicoidal groove aforesaid and rotate the drum and with it the signal lever until
the latter is caught behind its detent. On the said drum is a contact which is, by
rotation of the drum, brought into contact with a contact spring thus setting the
respective station to be called in circuit with the contact arm and the clock driven
frame.
When an electrically operating signal bell is used, the detent may have a double
escapement, the first detaining hook releasing the lever when the armature governing
the detent is attracted by passage of a current, and the second hook receiving it

page_text: until the passage of current ceases and the said armature fans back agam
electromagnet.
When a mechanically operated bell is used, this detent will have a triple
escapement as hereinafter described.
Reference being made to the annexed drawings
Fig. 1 illustrates that portion of the apparatus which is located at the central
station or place such as at the hotel office, the cover plate of the apparatus with its
dials being removed, to show part of the internal mechanism.
Fig. 2 is an elevation of the same apparatus from the back with the rear
enclosing plate removed.
Fig. 3 shows on a larger scale in rear elevation part of the mechanism shown
in Fig. 2.
Fig. 4 is a detail view in plan, partly in section, of part of Fig. 3.
Fig. 5 is a front elevation on the same scale as Fig. 3, of part of the mechanism
shown in Fig. 1.
Fig. 6 is a vertical section on line x x in Fig. 3.
Figs. 7 to 10 are views of the clock movement...
Figs. 11 and 12 show the mechanically operated signal bell as constructed for
fitting in any one of the rooms or places to be called.
Fig. 13, is a diagram illustrating the wiring or electric connections.
The apparatus essentially comprises a parallelogram f, g or a similar frame so
guided that it may be given a circular movement while preserving its orientation,
this frame carrying a number of contact pieces which will thus be each moved with
a simultaneous and in every respect equal rotary movement, a clockwork a for
revolving the said frame, a plurality of devices z adapted to be severally adjusted
or set to indicate the desired time at which the call is to be transmitted at which
time contact will take place with the respective contact piece on the aforesaid
frame f g these devices being indicated by Z1, Z2, Z3 (Fig. 13) and being equal in
number to the number of places to which calls may have to be transmitted; an
equal number of indicators 2 (for the return or acknowledging signal) and commu-
tators combined with the setting devices; a number of signal bells W¹, W³, W³ at
the places to be called, and lastly a device adapted to cause an intermittent action
of all the bells in the system in case of emergency.
The devices f, g, Z are mounted by preference on a tablet or insulating plate
enclosed in a case of which the front cover may be of coloured glass or other non-
transparent material and provided with a number of dials having also preferably in
the spaces within the circle of figures on the dial, transparent parts through
which the return signal disk 2 may be rendered visible when the signal is given.
The cover is also perforated for the passage of, or to provide access of a key to,
the square slotted ends of the shafts of the setting devices. The construction of
this cover will be well understood and it is therefore not illustrated, the circum-
ferences of the dials being shown with some of the figures thereon in dotted lines
in Fig. 1. The rear of the case may also be closed by a transparent cover
and the case may carry in practice a number of terminal binding posts for the
various wires as will be well understood without illustration, the method of wiring
being sufficiently indicated from the diagram in Fig. 13.
The clock a is preferably placed above the case and the frame f g is connected
to the rotary crank c' (Fig. 2) which is connected in any suitable way to the hour
wheel of the clock-work so as to revolve once for instance in each twelve hours; a
suitable number of rotary cranks e having their bearings in the plate are connected
to the frame fg and guide it in its movement of rotation so that it maintains its
orientation and every point of the frame describes an equal circle.
The frame f, g carries as many laterally projecting contact pins as there are
setting devices Z. The hollow axes Z2 of the setting devices carry indicating
fingers Z' Fig. 6 by which they may be set with regard to the figures on the dial,
that is to say to point to the time when the call is next required, and on said axes.

page_text: are also the spring contact arms d the position of which consequently accords with
the indicating finger so that the pin on frame fy will make contact with the
spring contact arm d at the time indicated.
To provide for exactitude in contact, the end of the arm d is widened, and bent
to a curve or an angle as shown in Fig. 6 and on to one edge of this angularly bent
part is slipped a piece of insulating material which reaches to the angle or ridge
of this bent part. As the pin in its movement arrives against, the insulating
piece it slips along the latter, at the same time pressing back the spring arm d until
the pin falls off the end of the insulating piece onto the ridge of the part thus
suddenly making efficient contact where the tension of the spring arm due to its
deflection is the greatest. Thence the pin slides in contact with the metal part i
of arm d until it passes off the latter.
The rear end of the hollow shaft Z2 (Fig. 6) is slotted longitudinally to receive
across pin Z against, which a spring plate Z presses partly by its own resilience,
partly assisted by a small coiled spring Z between it and the arm d. One end of
spring plate Ze is fastened to the plate H and the effect of the spring pressure
aforesaid is to keep the plate Z towards the surface of plate H. Contact is
also thus maintained for passage of electric current. The purpose of the spring
plate Zo is to return the answering sigual disk to its hidden position when the
device is being set and to adjust a commutator to bring the respective place to be
called into circuit. For this purpose the free end Z' of the plate Z forms a tooth
which engages in a helicoidal groove.Z" in the sleeve or drum Z8, keyed on the
shaft of the rocking arm which carries the answering signal disk v.. The
interior of the arbor being squared serves to receive a key by the rotation of which
this arbor may be set as before described while the insertion of such key causes its
inner end to meet and displace the cross. pin so as to press back the plate Z, the
tooth Z of which thus rotates the sleeve Z8 and with it the shaft sufficiently to
lift the arm with its disk v2 into a position where it is not visible and where it
will be then retained as shown in dotted lines in Fig. 5 by a pin 4 on the drum v
engaging behind the detent vo. are two electromagnets and is a pivoted
armature the fulcrum of which is at between the said magnets. The detent
plate is in one with or fixed to this armature and is provided with the three
detents and v10.
:
To provide for bringing the respective place to be called into circuit by the same
adjustment the sleeve Z8 (Fig. 3) carries a pin Z and in proximity thereto a
contact spring Zo is fixed so that the aforesaid rotation of the sleeve Z causes the
pin Z to come into contact with the spring Zo deflecting the latter against the
spring contact Z¹³ and remaining in contact therewith. The helicoidal recess Z
in the sleeve Z is cut with its one face parallel with the axis so as to permit the
nose Z' to return as shown in Fig. 4 without interference from the sleeve.
The electromagnets are wired in series with the battery E (Fig. 13) and the
signal bell W, W or W³ shown in detail in Figs. 11 and 12. The circuit passes
on the one hand to the frame f, g, and on the other hand from electromagnets v to
spring Z, through springs Z1, Z2 to spring plate Z and to arm d. The circuit
is complete when the spring in the course of its movement comes into, contact
with the conductive part. of arm d; the magnets and w* are thus energized.
The attraction of the armature moves the detent 10 from under the pin d
(Fig. 5) and brings the detent into the path of said pin, so that the arm v₁
falls slightly until the pin v is arrested by detent v, this displacement communicated
to sleeve Z being insufficient to destroy contact between pin Z' and springs Z10, Z18,
and this position continues until current ceases to pass through the coils of
magnets when the armature v will return to its first position causing the pin v
to arrive in the third detent vỡ.
Inasmuch as an ordinary electric bell would produce a cessation of current at the
first stroke which would de-energize the magnets v and cause the bell. circuit to be
immediately broken, we may adopt a construction to provide a shunt passage for

page_text: allowing a continuous current until the occupant of the room or place called
answers the call by placing the signal bell out of circuit. But to make a minimum
of current suffice for actuating the alarm posts, which avoids the danger that may
arise that on a simultaneous action of a certain amount or of all the alarm posts the
available current should prove insufficient, we prefer to use mechanical signal bells.
which can be released by a comparatively weak, short lasting current and which
are also so arranged that the traveller or person called has to rewind the
mechanism and thus occasions a controlling signal to be made visible at the
central post.
It..
Such electric freed mechanical signal bell is shown, in Figs. 11 and 12.
consists of a mechanical signal work actuated by a spring w. The hammer w' is
fitted with an attachment which is arrested by armature w³ of electromagnet w
standing under the influence of a spring we which thus opposes a resistance to the
oscillatious of the hammer. On energizing the magnet the arinature will be
attracted by the poles w and thus the hook shaped attachment w² looses its support.
and the hammer is freed. In view of only a short duration of current, the
armature will be kept in a downward position (that is to say out of reach of
the hammer attachment w²) by insertion of an angle lever w³, we also influenced by
spring w, into a fixture w attached to the armature which prevents the latter from.
being again raised by the spring w. The signal work can be thus run down
without hindrance. On the turning, just described, of angle lever wow in the
direction of arrow 1 (Fig. 11) a circuit pin w10 fastened to arm w will be removed
at the same time from a spring winsulated from the metal framing of the signal
work, and the current will thus be interrupted, which has as a consequence at the
central post the engaging of pin behind hook v.
+
It is intended that the guest or traveller called by the alarm should stop the
datter by pulling a cord 12 (Fig. 11) downwards.
By this movement the spring wis wound up, and tappet w4 fixed on the axle of
wheel w¹³ is turned in the direction of the arrow 2 (Fig. 11). Tappet w* thus
touches the arm w8 of the angle lever which is pushed back until the end piece of
arm w touches part w. The detent w³ of the armature thus has its support
withdrawn and the armature lifted again by spring wo intercepts again the bell
hammer w² w¹; at the same time pin wo is again brought into circuit thus causing
a current to pass releasing at the central station the signal arm from the hook 8.
and the signal plate v² will fall into view, (Figs. 1 and 5).
To make the contact of cam w14 against arm w8 (Fig. 11) dependent on ithe
tension of the spring w and thus prevent the giving of the return signal and the
putting out of circuit of the respective alarm post, until the spring w has been fully
wound, a spiral spring w18 is coiled on axle wl of angle lever w w one end of
which spring touches point w" of the axis and the other lengthened end w¹ is laid
against the main spring w. As the work runs down the angle lever turns more and
more in the direction of the arrow whereby w8 is moved out of the way of the cam;
when winding the arm w18 allows of a gradual turning back of the angular lever
until on the last turn of the wheel w13, cam w14 touches the arm wand moves the
angle lever completely to the side.
The binding post w is connected with the central station and the post w20 with
the battery. The coil w is connected at one end directly to post w at the other
end with the metal housing standing in direct relations with pin wls.
To permit the attendant at the central station to send at any time an alarm to all
the stations in the system the following construction is added.
t is a hand lever which in ordinary circumstances may be secured against
mischevious interference by a wire with a leaden seal. This lever t is connected by
link a¹0 (Fig. 1) to a lever a12.
1
The clock A is provided with two spring barrels a, a¹ (Figs. 7 to 8) of which
the one a actuates the clock-movement proper and a moves through the gear
train a³, a', as the crank of the frame fg. On the shaft a² of the crank c¹ is a finger a
:

page_text: which is arrested by a pin a' fixed on a second hour wheel a8 so that the rotation
of the parallelogram or frame f, g is restrained thereby to a slow rate synchronizing
with the movement of the hour hand of the clock. To provide for rapid rotation
of the parallelogram or frame f. g the wheel as is adapted to slide on the shaft a²
and is fitted with a sleeve a engaged by the fork of a spring lever at which is
adapted to be moved laterally by the curved arm all of the lever a¹² so as to
displace the wheel a² and disengage the finger a from the pin a' (Fig. 9) leaving
the action of the spring barrel a¹ uncontrolled.
Simultaneously with the disengagement of the running train is freed a spring t
(Fig. 2) in normal position kept aside by lever t, which draws with its free forkel
end (Fig. 2) the axis t³ of arm and thus brings the latter within the range of a
contact and catch pin fitted on one of the rods f, which pin h takes with it
the arm 2 (Fig. 2) and thus revolves a contact arm t fixed on the opposite endl
of the axle 3 (Fig. 1) and hereby circuits are formed rapidly through contact
pins t connected with the alarm stations through branch circuits.
This latter arrangement serves to give the alarm, in case of danger, to all the
alarm stations. By the rapid revolving of the rods the pins will come in contact
with the circuit arms d, i, but a certain number of the alarm stations might have
been put out of circuit, this makes it necessary for the alarm apparatus to .connect
with each station by a branch circuit closed by an alarm circuit pin. The
formation of circuits is done quickly one after another and not simultaneously, as it
is preferable especially with a large installation and in case of danger not to
entrust the available current with more work than it can do with sufficient security
and certainty.
When in case of danger the ruuning train is released from the regulator-clock
and the arm 2 is brought into the turning plane of pin ', the current coming from
the battery passes through the parallel frame f g to pin h¹ and arm t2; it will then
pass by spring t quickly and one after another to each of the circuit pins to and
from the latter through the several branch circuits to the alarm stations, 1, 2, 3, to
return to the battery by the return circuit.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that wha
we claim is :-
In electric call systems
:-
1. The combination of a plurality of open electric circuits, an electric signalling
device in each circuit an adjustable contact arm adapted to be traversed by the
current and forming the one termination of each open electric circuit, a rotary frame
common to all the circuits adapted to be traversed by the current and forming the
other termination in common of all the open circuits, means for preserving the
orientation of said frame, a clock for operating the circular movement of
.the frame, and a plurality of contact members on said frame adapted severally
to have contact with the aforesaid contact arms and thus complete the respective
circuit.
2. The combination in a circuit of a source of electricity an automatically
disconnected commutator, an electromagnet having an armature carrying a multiple
detent adapted to retain said commutator in position to establish contact, a signal
bell, an adjustable contact arm and a movable time controlled contact member
adapted to close the circuit by contact with said arm, said armature and detent
being adapted to release the commutator after make and break of a circuit operated
from the place called substantially as set forth.
3. The combination in a circuit of a source of electricity, an automatically
disconnected commutator, an electromagnet having an armature carrying a detent
adapted to retain said armature in position to establish contact, a signal bell
adapted to continue in operation after break of current, a hand switch, an adjustable
contact arm, and a movable time controlled contact member adapted to establish

page_text: the circuit by contact with said arm, said armature and detent being adapted to
release the commutator after make and break of a circuit established from the place
called substantially as set forth.
4. In a circuit a source of electricity an electro magnet, signal bell mechanism,
an adjustable contact arm at the calling station and a movable time controlled
contact member adapted to be traversed by the current and to close the circuit by
contact with said arm, in combination with a visible signal arm adapted to
automatically move into view when released an armature adapted to be moved by
the aforesaid electromagnet and a multiple detent on said armature adapted to
retain said signal arm from view and to release the same upon make and break of
the circuit established at the place called for the purpose set forth.
5. In a circuit, a source of electricity, a rotary commutator an electro-magnet,
an adjustable contact arm and a movable time controlled contact member adapted
to make contact with said arm at the calling place, together with a signal bell
mechanism, in combination with an arm integral with said commutator, a signal
disk on said arm, a movable armature for said electromagnet and a multiple detent
controlled by said armature and adapted to retain said commutator arm, thus
closing circuit at the commutator and holding the signal out of sight and to release
the same after a make and break of circuit established at the place called for the
purposes set forth.
6. The combination with a casing having a window therein, of a signal arm freely
suspended above said window to be visible thereat when free, a pin v on said signal
arm, an electro magnet v, a pivoted armature v adapted to be laterally attracted
by said magnet, a detent 7 integral with said armature, having hooks in
different planes, the said hooks being adapted to retain the pin respectively
before, during and after the passage of a first current through said electromagnet
and to release the said pin upon the passage of a second current.
7. The combination with the contact arm d of a shaft thereto adapted to receive
a key for rotary adjustment of said arm, a spring plate 2 adapted to be displaced
by inthrust of said key, a tooth Z on said plate, a sleeve Z having a helicoidal
groove Z receiving said tooth a shaft v for said sleeve an arm el on said shaft and
a detent adapted to receive and retain said arm when raised by the inthrust of said
key through the aforesaid, tooth, sleeve and shaft.
8. The combination with the signal arm vl, means for raising the same and a
detent for retaining said arm when raised, of shaft carrying said arm, sleeve Z³ on
said shaft, pin Z in said sleeve and contact spring Z10 located to be in contact with
said pin, and spring Z¹³ when arm v¹ is raised, and out of contact therewith when said
arm has fallen, for the purposes set forth.
9. A rotary contact arm constructed to be resilient in the plane of its pivotal
axis and of its extension from that axis, said arm having its outer end widened and
having its lateral edges bent rearward from a central radial line and having over one
of said edges au insulating cover extending from its edge up to said central line, in
combination with a contact pin adapted to be moved to pass onto said insulating
cover and deflect said arm while sliding on said cover, prior to making sudden
contact with the arm on slipping off the cover onto the centre of the end of the arm
substantially as set forth.
10. The combination of a series of adjustable contact pieces, a second series of
contact pieces, a displaceable device adapted to be rotated to make contact with the
one series of contact pieces, a motor for moving said device to make intermittent
contact, means for displacing said device or a part thereof to bring same into the
field for contact with the other of said series of contact devices respectively, and
means for accelerating the action of the motor when the device is in the field for
contact with the second series of contact pieces, for the purpose set forth.
11. The combination of a rotary contact making frame, cranks for supporting and
maintaining the orientation of said frame, a spring barrel for revolving one of said
cranks, a clockwork having an hour-wheel carrying a detent, a finger in operative
B

page_text: connection with said spring barrel adapted to be restrained by said detent, and
means for displacing said hour wheel and detent from the path of said finger for the
purpose set forth.
Dated this 1st day of October 1895.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicants.