Improvements in Alarm Clocks.
Year: 1892

page_text: Date of Application, 10th Sept., 1892
Complete Specification Left, 8th June, 1893-Accepted, 9th Sept., 1893
Improvements in Alarm Clocks.
1, THOMAS WILLIAM WOOD, of the Maynard Arms Hotel, Carlin How, in
the County of York, Innkeeper, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in alarm clocks.
In this class of clocks as at present constructed, the alarm is set in motion at the
selected time by adjusting the position of the setting dial which controls the stop
piece and frees the alarm mechanism, the alarm spring thereupon runs down and
must be rewound previous to giving another alarm, except that in some cases
provision is made for arresting the alarm at will as soon as it has fulfilled its
intended purpose which is generally to arouse a person from sleep.
The means employed for the purpose of arresting the alarm at will take the
form of a, detent lever which prevents the rotation of the alarm mechanism by
intercepting an arm or prong which extends from a high speed spindle connected
thereto. This detent lever extends through the clock casing and is operated by
hand from the outside. Such detent levers as are at present in use for this purpose
remain in the locking position until put out by hand and must therefore receive
attention before the alarm can be operated again, and clocks so constructed
consequently require as much attention as when the alarm mechanism must be
rewound for each operation.
The object of my invention is to so coniect a detent lever of this kind with other
mechanism that it can be used at will for stopping the alarm and without further
attention is afterwards automatically removed from the locking position, leaving the
alarm free to act again when the setting dial comes round to the same hour of the
next day.
In carrying out my invention, I construct the detent lever with two prongs, one
of which engages with the arm or wire on the high speed spindle of the alarm
mechanisin, whilst the other prong rests on or near to what may be termed a
24 hours wheel geared into a 12 hours wheel at the back of the setting dial.
This combination of mechanisin is arranged and adjusted to act as follows:-
The detent lever having been left in the locking position at the last alarm remains
there until a cam or its equivalent on the 24 hours wheel comes round to the
position which brings it in contact with the lower prong which then lifts up and
puts the detent lever out of action; the arm or wire then turns over and occupies
its normal position on the stop piece until released for the next alarm in the
ordinary course. As the alarm is usually required to repeat itself once only in each
24 hours, that is once in every second cycle of the clock's motion, provision is made
in connection with the 24 hours wheel by which the detent lever is not put out of
the locking position until the time at which the alarm would operate in the first
cycle of 12 hours has passed, that is to say that if the alarm goes off at 6 in the
morning, it will not be released from the detent lever until after 6 o'clock at night,
when, it is not required, but would go off if free to act.
Dated this 9th day of September 1892.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Alarm Clocks.
I, THOMAS WILLIAM WOOD, of the Maynard Arms Hotel, Carlin How, in
the County of York, Innkeeper 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 improvements in alarm clocks.
In this class of clocks as at present constructed the alarm is set in motion at the
selected time by adjusting the position of the setting dial which controls the stop
piece and frees the alarm mechanism immediately when the time indicated upon the
clock dial by the position of the hour hand corresponds with the time similarly
indicated by the hour hand on the setting dial and this occurs at the first transit of
the setting dial and hour hand over this position on the clock dial after setting and
winding up the alarm mechanism that is to say, within the cycle of the current
12 hours. The alarm spring thereupon runs down and must be rewound previously
to giving another alarm except that in some cases provision is made for arresting
the alarm at will as soon as it has fulfilled its intended purpose which is generally
to arouse a person from sleep.
The means employed for the purpose of arresting the alarm at will, take the
form of a detent lever which prevents the rotation of the alarm mechanism by
intercepting an arm or prong which extends from a high speed spindle connected
thereto. This detent lever extends or projects through the clock casing and is
operated by hand from the outside. Such detent levers as are at present in use for
this purpose remain in the locking position when once used until again put out by
hand and must therefore receive attention after each use before the alarm can be
operated again. Clocks so constructed consequently require as much attention as
when the alarm mechanism is allowed to wholly run down so as to require rewinding
for each operation.
In consequence of the improved arrangement of mechanism constituting my
invention a detent lever of this kind is so connected with other mechanism that it
can be used at will for stopping the alarm and without further attention is after-
wards automatically removed from the locking position leaving the alarm free to
act again when the setting dial comes round to the same hour of the next day and
by suitably adapting the alarm mechanism to the time keeping mechanism of the
clock the necessity of winding the alarm mechanism up at frequent intervals
relatively to the intervals of winding the time keeping mechanism can be
dispensed with, that is to say that the alarm mechanism in regular use can be
designed to run itself down in daily stages of sufficient duration to effect its
purpose in not less time than will exhaust or run down the time keeping
mechanism.
My invention is therefore especially serviceable when applied to an eight day
clock.
Having described the nature of my improved alarm mechanism and its utility, I
will now proceed to further explain the same by reference to the drawing hereto
annexed and the manner in which my improvements are to be carried out in
practice.
The general construction of the clock so far as it is shown in the drawing is to
be taken as representative of alarm clocks generally, the precise arrangement
indicated by the drawing being given for the purpose of illustration only.
In carrying out my invention 1 construct the detent lever a with two prongs a¹ a²
of which the prong a' engages with the arm or prong b on the high speed spindle c

page_text: whilst the other prong a² rests on the snail or cam & which is secured to and rotates
with what I term the 24 hours wheel e, the central parts of which are omitted from
the drawing to show the position of snail more clearly. This 24 hours wheel gears
in the ratio of 2 to 1 into the wheel which is secured to the back of the setting
dial g so as to be carried round with the hour hand arbor once in every 12 hours;
is the usual alarm stop piece which rocks about the pin with its free end h²
resting upon the boss g at the back of the setting dial, the groove g² of which
allows the said stop piece to drop down once in 12 hours to the position shown in
dotted lines so as to be out of reach of the prong b when the time arrives for the
alarm to go off as indicated on the setting dial. ³ is a connecting rod for operating
the detent lever a by hand from outside the clock case at will, and the pulley k and
spring constitute a friction brake for retaining the detent lever a in any required
position to which it may be lifted whether by the snail or by hand.
The above described combination of parts the use and arrangement of which
constitute the essential feature of my invention are intended to operate as follows:-
The detent lever a, having been left in the locking position at the last alarm as
shown in the drawing by full lines, remains there until the cam or snail d on the
24 hours wheel e comes round to the position which brings it into contact with the
lower prong a² and the detent lever is then lifted up to the position shown in dotted
lines and out of reach of the arm or prong 6 of the high speed spindle c, this arm
or prong, then turns over and occupies its normal position on the stop piece /
until released for the next alarm in the ordinary course. As the alarm is intended
to repeat itself once only in each 24 hours, that is, once in every second cycle of
the clocks motion, the object of the combined action of the wheels e and ƒ and
snail or cam d in conjunction with the detent lever a is to arrest the motion of the
alarm mechanism when freed from the stop piece h, in the first cycle of the clocks
motion after the last alarm but not in the second. This is effected by setting the
snail or cam of the 24 hours wheel at such a position relatively to the groove g²
in the boss of the twelve hours wheel, that in the first place the said groove y² gets
once past the position at which the stop h can drop down clear of the alarm
mechanism before the detent lever a is lifted clear of the arm or prong by the
snail or cam d, but before the groove 2 passes this position a second time, the
snail d has lifted the detent lever a out of the locking position to the position
shown in dotted lines in which it remains until drawn back by pulling out the
connecting rod a³ from the position shown in full lines. Any tendency of the
lever to move of itself is prevented by the brake action of the spring and
roller k.
A consequence of the above described improvements in the alarm mechanism of
clocks is that the alarmn is intended to go off at any given time once in 24 hours,
say for instance at 6, o'clock each morning the alarm mechanism although released
from the usual stop piece at 6, o'clock at night cannot go off at that time on
account of the detent lever a, but when again released by the dropping of the
stop piece a second time that is at 6, o'clock next morning, is then free to go off,
the detent lever a, having been lifted up at some time after 6, o'clock of the night
before by the movement of the clock itself. Consequently the alarm can be stopped
at will each time it is set off and may then be left to itself to go off again at the
proper time without further attention.
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 :-
The combination with the alarm mechanism of a clock having a detent lever for
stopping the alarm at will, of a wheel geared into a wheel on the hour hand arbor
and furnished with a snail, cam or its equivalent for lifting the said detent lever out
of the locking position whereby the said alarm can be set to go off once only at
any desired time in each 24 hours, the said alarm mechanism being constructed
arranged and operating substantially in the manner and for the purpose as

page_text: herein before described and illustrated by way of example in the accompanying
drawing.
Dated this 7th day of June 1802
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.