Improvements in Alarm Clocks.
Year: 1891

page_text: Date of Application, 16th Apr., 1891-Accepted, 23rd May, 1891
COMPLETE SPECIFICATION.
Improvements in Alarm Clocks.
I FRANK ROTHWELL, of Clarendon Place, May Street, Belfast in the County
of Antrim, Merchant, 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 my invention is to provide an electric alarm clock which, when the
circuit is completed, will ring an alarm bell and continue ringing same until the
circuit be again broken; and in carrying my invention into practice I place a clock
of ordinary construction upon, or near to, an electric battery, and connect a wire
from one pole of the battery to the clock, and then lead another wire from the
opposite pole of the battery to a moveable metal pin for insertion in the face or
dial of the clock in the manner to be hereafter described.
The clock is surmounted by, or otherwise connected to, a bell such as is ordinarily
used in combination with electric batteries, in such a manner that upon the circuit
being completed a current of electricity causes the bell to ring and to continue
ringing until contact is broken by removal of said metal pin from the face or dial of
the clock. This dial should be of insulating material.
To enable my invention to be understood, I will now describe the annexed
drawing, in which A is a clock worked by an ordinary spring and mechanism,
surmounted by an alarm bell B, and resting upon a base C containing an electric
battery, one pole of which is connected by an insulated wire D to the clock.
The opposite pole of the battery is connected by an insulated wire D' to a
moveable metal pin E, the use of which will be hereafter explained.
I may supplement the two usual or chronometric hands of the clock by an
additional or electric hand F which revolves with the hour hand and upon the same
spindle, or I may if found desirable dispense with the ordinary or chronometric
hands and use the electric hand by itself."
The dial near its outer circumference is punctured with an arbitrary number of
equidistant holes G G, each hole marking a division of time, that is to say, should a
dial representing the twelve hours be surrounded by forty eight holes then each hole
will mark an interval of a quarter of an hour.
The objects for which the holes are made is to enable the alarm bell to be set to
ring at any given time and this is provided for by the following device :-A crystal
face is fitted in front of the dial which is free to be revolved in its frame and it is
pierced by a single hole H in such a manner that this hole H may by revolving the
crystal face in its frame, be brought opposite to any one of the equidistant holes in
the dial, in which the pin F may then be inserted by passing it first through the
hole H in the moveable crystal face; the position of the pin then indicates the
exact time at which the alarm bell will ring when the electric hand moving round
with the hour hand, will touch it and so complete the circuit. According to my
invention this result is effected when the electrical hand F, which extends beyond
the hour hand of the clock touches the said metal pin E, when the electric circuit
is completed causing the bell B to ring and to continue to ring until the current of
electricity is stopped by removal of the pin E.
Continuance of contact of the electrical hand F with the pin E is ensured by the
frictional adherance caused by the centre spindle D of the clock, carrying the hour
hand, which continues to revolve, so that the mechanical motion of the clock is not
interfered with during the ringing of the alarm.

page_text: The crystal face and its frame may be removable to enable the electrical hand F
to be re-adjusted so as to again coincide with the hour hand of the clock.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is:
First In electrical or other clocks, the use of a moveable revolving crystal
outer face or glass having drilled or formed therein at a certain point, a hole corre-
sponding with holes in and around the dial of the clock, when such outer face is
revolved in its case or bearing substantially as described.
:
Second In electrical alarm clocks, the combination of a fixed dial having holes
around the face thereof, a loose revolving crystal face or case having a single hole
therein corresponding (on the face being revolved) with each of the holes in the
said dial, a pin electrically connected with one pole of a battery and an electric
bell, and capable of being passed through the hole in the face and fixed in one of
the holes in the dial; and an arm fixed on the spindle of the clock for the purpose of
making electrical contact with the aforesaid pin, the said clock being connected to
the opposite pole of the battery and the electric bell substantially as described.
Third The electric alarm arrangement for clocks substantially as herein before
described and as partially illustrated by the accompanying drawings.
.
11001
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, London, W.C., Agents for the Applicant.