Gravitation Time Alarm.
Year: 1891

page_text: Date of Application, 5th Oct., 1891-Accepted, 7th Nov., 1891
COMPLETE DIECIFICATION.
Gravitation Time Alarm.
1, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Philip Hathaway, of 112 White
Street, in the City and State of New York, in the United States of America,
Electrician), 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 the invention is to provide a new and improved gravitation time
alarm, which is simple and durable in construction, and adapted to sound an alarm
at a given predetermined time.
The invention consists of a graduated rack set in a vertical position, a frame fitted
to slide on the said rack and containing a train of gear wheels controlled by a
pendulum escapement, one of said train of gear wheels being in mesh with the said
rack, and a gong adapted to be sounded by the said frame on reaching the lower-
most position.
The invention also consists in certain parts and details and combinations of
the same, as will be hereinafter fully described and then pointed out in the
claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
both the figures.
Figure 1 is a front elevation of the improvement, with parts in section; and
Figure 2 is a side elevation of the same, with the frame in section.
The improved alarm is provided with a suitably constructed base A, on which is
erected a post B, having on its front a graduation C indicating hours, minutes, and
subdivisions. On one edge of the post B are formed rack teeth D which terminate
a suitable distance above the top of the base A. On the post B is fitted to slide
vertically a frame or casing E, in which is mounted to turn and to slide transversely,
a main shaft F projecting a suitable distance beyond the front plate of the frame o
casing E, the outer end of said shaft being provided with a button F¹ adapted to
be pressed by the operator.
On the main shaft F is secured a pinion G in mesh with the rack teeth D, and
adapted to be disengaged from the same by pressing the button F¹ so as to slide
the shaft F rearward to move the said pinion out of mesh with the rack teeth D.
A spring H secured in rear of casing E, presses against the rear face of the pinion G
so as to hold the latter in mesh with the rack teeth D, until moved out of mesh as
above described, by pressing the shaft F so as to compress the spring H. When
the operator releases the pressure on the button F¹, the spring H forces the
shaft F, consequently the pinion G, into its former normal position illustrated in
Figure 2.
On the main shaft F is also secured a gear wheel I, in mesh with the pinion J
secured on a shaft K arranged transversely and mounted to turn in suitable
bearings formed in the frame or casing E. On the shaft K is also secured an
escapement wheel L, adapted to be acted on by an escapement N of any approved
construction, and secured on the shaft N' mounted to rock in suitable bearings on
the casing or frame E. The escapement shaft N' is constructed in the usual
manner with a pendulum O, extending through the bottom of the casing to the
outside.
The under side of the casing or frame E is adapted to engage the free end of a
striker P, provided on the top of the base A and adapted to sound a gong Q also

page_text: The operation is as follows:-
When the alarm is at rest, the frame or casing E is in a lowermost position,
resting on top of the base A, the pinion G then being in a lowermost position and
out of mesh with the rack teeth D. When the operator desires to use the alarm,
he presses on the button F¹ so as to move the pinion out of the path of the rack
teeth D, and then the operator lifts the frame or casing E to a desired position,
that is, until the top of the casing indicates at the desired place on the graduation C.
For instance, if it is desired to sound the gong Q fifty minutes after setting the
alarm, then the casing or frame E is moved up until the casing registers with the
50 minute mark on the graduation C. When the desired place has been reached,
the operator releases the pressure on the button F', so that the spring H moves
the pinion G in mesh with the rack teeth D. The operator then starts the
pendulum O and releases the frame or casing E, so that the latter can slide down-
ward by its own weight on the post B, the downward movement being gradual,
by the movement of the pendulum and the escapement N on the escapement
wheel L.
It is understood that the train of gear wheels connecting the rack teeth D with
the escapement, is proportioned so that the frame or casing E moves downward
until the pinion G leaves the last rack tooth D at the time indicated. The
moment the pinion G leaves the last tooth, the frame E drops suddenly and strikes
against the free end of the striker P, so that the gong Q is sounded, indicating that
the time for which the alarm has been set is expired.
It will be seen that the aların contains no actuating springs, but depends solely
on the gravitation of the casing E on the post B. The alarm may be used for
timing the cooking of food, the duration of lessons in schools, or of lectures or
speeches, and for various other purposes where an audible indication of the expiration
of any short period of time is required.
Having thus particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is:-
1. A gravitation alarm comprising a gong, a casing or frame adapted to slide
vertically and to actuate the said gong, and a train of gear wheels controlled by a
pendulum for regulating the downward movement of the said casing or frame,
substantially as shown and described.
2. A gravitation alarm comprising a post formed with a graduation and rack
teeth, a frame adapted to slide on the said post, and a train of gear wheels in mesh
with the said rack teeth and controlled by a pendulum, substantially as shown and
described.
3. A gravitation alarm comprising a post formed with a graduation and rack
teeth, a fraine adapted to slide on the said post, a train of gear wheels in mesh
with the said rack teeth and controlled by a pendulum, and a gong adapted to be
sounded by the said frame on reaching its lowermost position, substantially as shown
and described.
4. In a gravitation alarm, the combination with a post having rack teeth, of a
frame fitted to slide thereon, a pinion in mesh with the said rack teeth, an
escapement wheel connected by a train of gear wheels with the said pinion, and a
pendulum escapement acting on the said escapement wheel, substantially as shown
and described.
5. In a gravitation alarm, the combination with a post having rack teeth, of a
frame fitted to slide thereon, a pinion in mesh with the said rack teeth, an escape-
ment wheel connected by a train of gear wheels with the said pinion, a pendulum
escapement acting on the said escapement wheel, and means, substantially as
described, for throwing the said pinion out of mesh with the rack teeth, as set
forth.
6. In a gravitation alarm, the combination with a post having rack teeth, of a
frame fitted to slide thereon, a pinion in mesh with the said rack teeth, an escape.

page_text: 3
ment wheel connected by a train of gear wheels with the said pinion, a pendulum
escapement acting on the said escapement wheel, and a gong adapted to be sounded
by the said frame on reaching its lowermost position, substantially as shown and
described.
Dated thin 5th day of Andah 1001
ALLISON BROS.,
Agents for the Applicant.