IMPROVEMENTS IN ELECTRIC CLOCKS WITH A METHOD FOR STRIKING HOURS AND HOUSEHOLD ALARMS
Year: 1884

page_text: JOHN ESHELBY Tower Ville Sandmount Co. Dublin Watchmaker & Nautical
Optician do hereby declare the nature of my invention for IMPROVEMENTS IN
ELECTRIC CLOCKS WITH A METHOD FOR STRIKING HOURS AND HOUSEHOLD ALARMS
to be as follows :—
I
For propelling the dialwork and hands I adopt the usual arrangement for that
purpose, with momentry currents sent from driving clock each minute, viz., an
electro magnet the armature of which having a detent pivoted at upper extremity,
and furnished with a pin or claw, which acts upon the teeth of a wheel mounted
on horizontal axis parallel to armature, this wheel being held in position by a paul
while detent is driven forward, the wheel is carried forward one degree or tooth on
return of armature to rest.
Instead of the usual ratchet shaped tooth I use a straight tooth with 60 in the
wheel, I also add a detent pivoted near top of armature and extending parallel to
plane of wheel to its opposite side, this is furnished with a thin pallet at right
angles and placed so as to act between each tooth of wheel, locking wheel when
armature is at rest, and freeing it when armature goes forward. I may also use &
detent intervened between armature detent and the wheel, either fixed by spring
or pivoted, or invert the action.
For striking the hour I use the same arrangement, but having 102 teeth in the
wheel, with 12 pins passing through it in a concentric circle to and parallel with
axis and near to the teeth, and projecting equally on either side, and distant
from each other, respectively on the intersection of lines from following teeth to
centre 0-3-7-12-18-25 33-42-52-63-75-88 and 1020 & 102 being
identical.
From an insulated bar above I fix a spring contact so that an insulated nib near
extremity parallel to wheel comes in contact with each pin successively and is
lifted by them only during one movement of wheel, the space of one tooth,
remaining lifted when armature falls back last time in each number. On extremity
of spring I put a platinised contact in front, and a corresponding one on a rigid
piece for it to bear on when not lifted by pins.
A wire from this spring is continued to driving clock to one of a similar pair of
contacts the insulated nib of which acts upon teeth of any wheel having suitably

page_text: quick revolutions so that current would be interrupted as each tooth passes and
restored as often.
Another similar pair of contacts with nib acting on perifery of a disc attached
to cannon pinion or minute wheel of clock with one notch in it, coincident to the
minute band of clock pointing to the 60th minute when nib was in it, contact
being only made at that instant, and broken when lifted from notch, one half of
both intermittent and hourly contacts are joined, a common wire going from them
to battery polo and from battery to electro magnet terminal the other electro
magnet terminal going to the rigid contact piece of counter.
It is therefore obvius that except when contact is broken by pin lifting spring a
regular succession of pulsatory currents are transmitted through counter, only
terminated by following pin being lifted.
Another wire is led from the spare half of hourly clock contact to rigid part of
counter contact so that when hourly contact or warning is made the broken contact
is bridged and a current passed through magnet attracts armature forward, that
when current is broken falls back carrying wheel and releiving pin from contact
spring, continues till next pin lifts it and so on from 3 pulses to 14.
On opposite side of wheel I put similar but reversed contacts, and a pin from
detent of armature between them, but insulated from them so when armature falls
to rest contact is broken: an arbour pivoted in frame carries a spur or detent
which is lifted by the pins on other side of wheel during 2 motions of wheel,
coincident with 1 two pulsations of each number, and afterwards falls out of
action, while remainder of number is counted. Another spur from same arbour
between the spring and other contact and parallel to spring, just keeps it from
falling back into contact while detent is on tooth.
Wires from these contacts with a battery in line go away to any number of
electric bells either trembling or single stroke, if trembling but one bell has
contacts, remainder have wire passing directly from line over the bobbins.
Consequently as hand of driving clock goes or is set round, the hours from 1 to 12
are struck on every bell evenly.
The first 2 pulses are not struck by bells as one is the warning and the other
probably a very short contact are purposely cut out which explains the reason for
having 2 spare teeth each hour.
i
The same bells are used as household alarms as follows, joined to the spring
contact of bell relay, I place a second spring outside rigid contact piece on opposite
side, with contact parts platinised, this remains normally out of contact but I fix
a second electromagnet to frame, the armature of which when excited presses the
spring down and makes contact, I put a ratchet on arbour of armature with a paul
so acting that when drawn forward remains so.
This second electro magnet is in line with any system of burglår or other alarms
required, the line being fitted with a switch that may be broken in day time and
put on last thing at night, but if any points of alarm are interfered with after-
wards the entire system of bells ring continually and can only be stopped by person
in charge of machine.

page_text: JOHN ESHELBY Tower Ville Sandymount Co Dublin Watchmaker do hereby
declare the nature of my invention for IMPROVEMENTS IN ELECTRIC CLOCKS WITH
A METHOD FOR STRIKING HOURS OR HOUSEHOLD ALARMS and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
To enable any existing clock to strike the hours on any number of electric bells
simultaneously also to make use of same bells for burglar or fire alarms, and to
improve the ordinary electric minute motion dial work and render it reliable.
I add to any single part clock two insulated contact springs fig 3. D & E—
D being actuated either by the teeth of a train wheel or one specially mounted for
the purpose on say 4th wheel arbour A fig 3. and an insulated pallet on spring
pressing slightly on perifery of wheel, the teeth of which are divided to lift the
spring and lower it at convenient equal spaces of time, from its contact with
metalic frame D¹ fig 3. or I may cause pendulum to make and break contact for
same purpose or use both ends of contacts insulated.
Contact E from ebonite pillar or block to which D is fixed makes contact once
an hour for a few seconds only against a platinised tip on perifery of a disc fixed
to cannon pinion or minute wheel, circuit being completed through frame, or if
both ends are insulated and contact made by notch in disc or otherwise, the other
end should be joined by general wire to same end of D¹. In conneixon with these
contacts I put into line with battery the counter as shown figs 12 & 4*.
F is an electro magnet fixed at bottom between two parallel plates G in centre
of plates is mounted on horizontal axis a wheel with 102 straight teeth H furnished
with twelve steel pins passing through, wheel and projecting " on either side in
concentric circle and parallel to axis and distanced from each other by a radial
line on which first would be, counting 3 teeth then another pin, adding one tooth
each time from 3 to 14 completing 102.
The numbers would run from top of machine to heel of magnet or front to back.
The armature of magnet is carried by a light frame I. pivoted at lower end into
plates and extending to above height of top of wheel H. At upper extremity it
carries the axis of a bar K. extending over top of wheel and is pinned to a detent
pivoted in frame L. Against this detent is a spring to send armature back from
magnet readily.
In centre of bar is a click or pawl M which acts over top of wheel into the teeth
so that when magnet releases armature the pawl brings wheel forward one tooth
and in its reverse action toward magnet drops over the tooth, the wheel being

page_text: retained by second pawl pivoted in plate N. The detent L extends downwards to
same height as axis of wheel and is furnished with a thin edge turned at right
angles facing wheel, and so adjusted as to fall into teeth as armature goes to rest
locking it and preventing more teeth than one going forward at one time. I may
also use a ratchet shaped tooth in which case I use two wheels on same axis one
for pawl to act into and move wheel the other reversed into which detent acts.
Between the frames I put 2 ebonito pillars P. fig 4 one at top above front edge of
wheel the other in vertical line beneath just above magnet. From the upper
pillar at right side of wheel and extending downwards I plant a spring O. 1. and
resting other extremity with platinised tip on plate O. 2. fixed to lower pillar and
furnished with insulated pallet P. which is so adjusted in length and shape that
each pin in the wheel as it comes round lifts it and breaks contact. My line from
clock escapement D spring is run to the upper part of spring O¹ the magnet coils
have one terminal fixed to plate O the other terminal goes through battery to
plate of clock or general clock contact completing circuit.-I run another wire from
insulated discharge spring fig 3 & 4b E on clock to lower counter contact plate O 2
completing circuit during contact of disc and spring a few seconds each hour. It
will therefore be seen that when counter is at rest as in fig 2, with pallet raised
by 2nd pin on the hands of clock being turned round till contact is made
at E fig 3. Magnet is excited and armature draws pawl forward over tooth;
instantly contact is broken armature falls back carrying wheel with it and
disengages the pin from insulated pallet and renews pulsatory currents at regular
intervals from escapement after the first which might be a short one depending on
position of escapement contact when hourly contact ceased, these currents would
continue for five beats when 3rd pin lifting pallet would break contact, this would
remain inert until again set in motion by hourly contact being made & broken and
so on increasing one number each time to 14.
On the left side of wheel from lower ebonite pillar I plant a spring extending
upwards Fig 4 R¹ which makes contact on front side of a plate R³ on upper pillar,
an insulated pin projecting from bar K Fig 1. S. carries the spring with it backward
when armature falls to rest, breaking contact, which is made only as magnet
armature allows it when going forward. I also put an insulated pallet Fig 1 T. on
this spring of only sufficient breadth at point to keep it out of contact for two.
beats i.e. the warning from hourly contact and first or probably short beat from
escapement or pendulum, afterwards as armature goes forward contact is made
with perfect regularity and is passed through line with battery to Electric Bells,
only one of which has contacts, in any number of others the wire goes directly over
the magnet coils.
The machine is also furnished with a vertical electro magnet V Fig 1 & 2 set at
right angles to lower one the armature W of which is pivoted on an axis X
furnished with a ratchet and pawl the other extremity is carried forward close to
an auxiliary contact spring Fig 4 R³ which comes from plate of R¹ but is kept
backwards and only makes contact when armature going forward presses it against
the back of contact and keeps it there, the pawl locking ratchet until a pressure is
made on reverse end of pawl letting it free this line may be in connection with
any of the usual burglar or fire alarm systems and line may be broken in day time
by switch arrangement but when put on at night any interferance with contact
points would excite electro magnet and close contact which would ring continously
till freed at machine.
I also propose to use same arrangement of electro magnet &c with 60 teeth in
centre wheel instead of 102 and the extension of wheel arbour to form minute
pinion with ordinary dial work and locking as before described but without contacts.
Or double reversed ratchets as before mentioned but only of 60 teeth these to be
actuated in line from driving clock once a minute.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1st The counting machino substantially as described being seperate from yet
actuated by driving clock, in combination with Electric Bell relay as described.
2nd The use of electric trembling bells for striking the hours substantially as
described in combination with the use of same bells as household alarms.
3rd My improved locking for minute motion electric dials substantially as
described in combination with the striking machine.