An Electric Alarm Clock specially applicable for use in Public Works and other Institutions.
Year: 1898

page_text: Date of Application, 25th Nov., 1898
Complete Specification Left, 25th Aug., 1899-Accepted, 18th Nov., 1899
PROVISIONAL SPECIFICATION.
An Electric Alarm Clock specially applicable for use in Public Works
and other Institutions.
I, THOMAS MILLAR, 8, Tarvitt Street, Edinburgh, in the County of Mid Lothian,
N.B., Engineman, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an electric alarm clock specially applicable for use
in public works and other institutions in which it is required to notify the inmates
in the various departments, simultaneously, of certain specified hours.
For this purpose an eight day clock may be employed which when once wound
up will automatically ring the bell at the required times without further atten-
tion. This may be effected by providing the hour wheel which rotates once
every 24 hours with a disc having notches formed in the periphery thereof into
which a projection carried by the cranked arm of a pivoted lever can engage.
This lever carries a terminal which when the projection on the crank arm is in
the recess or notch of the before mentioned disc, completes the circuit of the electric
bell, causing it to ring. When, however, the projection on the crank arm is
forced out of the recess in the disc, by its rotation, the contact is broken.
In order to cause the contact to be completed at certain pre-arranged intervals,
and only at those intervals, a second disc may be employed geared from the hour
wheel so that it revolves once in seven days. The periphery of this disc is pro-
vided with notches into which a second arm carried by the contact lever engages,
the notches being so arranged as to enable the contact to be made at any inter-
mediate time between two hours. This disc may also be left clear for a seventh
of its circumference should it be desired to prevent the bell ringing on any par-
ticular day.
In cases where the hour at which the bell or bells have to be rung may require
to be varied, the seven day disc may be so mounted that it can be readily removed
and another having differently arranged notches substituted for it.
An Electric Alarm Clock specially applicable for use in Public Works
and other Institutions.
I, THOMAS MILLAR, 8, Tarvit Street, Edinburgh, in the County of Midlothian,
N.B., Engineman, do hereby declare the nature of this invention and in what
[Price 8d1

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to an electric alarm clock specially applicable for use
in public works and other institutions in which it is required to notify the inmates
in the various departments, simultaneously, of certain specified hours.
For this purpose an eight day clock may be employed which when once wound
up will automatically ring the bell or bells at the required times without further
attention.
But in order that my said invention may be readily understood and easily
carried into effect I will proceed to describe the same with reference to the accom-
panying drawings in which Fig. 1 is a front view of the mechanism I employ.
Fig. 2 is a side view shewing the position of the discs on the hour and minute
wheels, hereinafter referred to.
Referring to the said drawing I provide the hour wheel A which rotates once
every 12 hours, with a disc B having notches 6 formed in the periphery thereof
into which a projection or pin C carried by the cranked arm of the pivoted lever D
can engage. This lever carries at its upper end a terminal, switch or sliding
contact piece E which when the pin C on the crank arm is in the recess or notch b
of the disc B advances and completes the circuit of the electric bell, or bells,
causing it then to ring. When however the pin C in the crank arm is forced
out of the recess in the disc, the contact is broken.
In order to cause the circuit to be completed at certain pre-arranged intervals
and only at those intervals, a second disc may be employed geared from the hour
wheel by the intermediate wheel and pinions f so that it revolves once in seven
days. The periphery of this disc is provided or formed with notches G into which
a second projection or pin g carried by the lever I engages, the effect of the said
disc being to prevent the pin Centering the notch until one of the notches G
is presepted by the disc's rotation to the pin 9, the whole arrangement being such
as to enable the contact to be made at any hour, or intermediate time between
two hours. This disc may also be left clear for a seventh of its circumference
should it be desired to prevent the bell ringing on any particular day.
The notches may be so arranged in the hour wheel disc B that the bells will
ring at the desired specified times on each day whenever the notches in the two
discs are in a position to allow of the respective pins entering their notches, but
in order to ensure that the bells will ring at the desired time correctly to the
fraction of a minute, I attach a third disc H to the minute wheel which rotates
once every hour and provide it with the requisite notches h, this arrangement
avoiding the necessity of forming the notches in the hour wheel disc with such
precision as would be necessary were this third dies not employed.
notches in the disc H are rounded off or bevelled at one side so as to raise the
The
pins out of the recesses in the discs by their rotation.
The bell cannot be rung until the notches in the three discs are in their correct
relative positions ready to receive the two pins by simultaneously. In cases
where the hour at which the bell or bells have to be rung may require to be varied
at different seasons, the various discs may be so mounted that they can be readily
removed and others, having differently arranged notches, substituted therefor.
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
1. An electric alarm clock, applicable for use in public works and other institu-
tions, constructed and operating substantially in the manner as and for the pur-
poses herein before described and shewn in the accompanying drawings.
2. In an electric alarm clock, the combination with a sliding electric switch or
contact piece, actuated by a cranked lever, of a time regulating disc rotating with
the bour wheel, a similar disc rotating with the minute wheel and a wheel rota-

page_text: ting, once every seven days, the said discs being provided with notches for the
reception of pins on the switch lever, all arranged and operating substantially in
the manner as herein before described and shewn in the accompanying drawings.
Datod this 24th day of August 1899
JOHNSONS,
Applicant's Agents;
115, St. Vincent Street, Glasgow.