Improvements in Electric Time and Fire and like Alarms.
Year: 1899

page_text: Date of Application, 6th Feb., 1899-Accepted, 13th Jan.,
1900
COMPLETE
SPECIFICATION.
Improvements in Electric Time and Fire and like Alarms.
We, JOHANN WILHELM HERMANN WENDT, Master Builder, 12, Wettinstr.
Kamenz, and KARL LUDWIG KRAUSSE, Merchant, 24, Marchnestrasse, Dresden, do
hereby declare the nature of our said invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the follow-
ing statement:-
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-
The object of the present invention is an alarm or alarm-contrivance which
operated by a clock, by the aid of electricity enables an alarm to be given in
one or more places simultaneously or at definite intervals. Moreover it is possible
by a short-circuit arrangement in case of danger, e.g. the breaking out of fire,
to give a simultaneous alarm at all places in connection.
The object of the invention is illustrated in the accompanying drawings.
Figure 1 shews a front elevation of the contrivance.
Figure 2 a side elevation of the clock work.
Figure 3 shews a section of the same from above.
Figure 4 illustrates the switch dise for operating the alarm contacts.
Figure 5 shews a switch-board for applying the contrivance to manufactories
as a time indicator.
In the clock-work 1, which is operated in the usual manner, and does not
differ from an ordinary clock, a contact disc 2 is attached to the hour-wheel-
arbor, on which disc contact-pins are provided in the form of a curve shewn
in Figure 4. The number of these contact pins depends upon the number
of contacts employed and in the present instance, in which half hour alarms
are provided for, is twenty four.
Behind the clockwork there are twenty four contact springs 3 which are
operated in succession at half-hour intervals by the aforesaid pins, i.c. they are
raised and thereby pressed against a contact strip 4. From these several contact-
springs 3 wires 41 lead to the contacts 5, in which the holes 6 are situated. By
means of these holes 6 the circuit-cords 7, to the ends of which plugs are
attached in the usual way, can connect the contacts 8 & S¹ with the contacts 5
as desired the several alarms are in connection with the contacts 8 & S¹ so that
by means of the latter, as desired, the occupants of one or more different rooms
may be aroused at intervals of half an hour. Frequently and even for the most
part two or more of the said occupants are to be aroused at the same time and in
this case the corresponding contacts are connected by other cords as 7ª shown in
Figure 1 and coupling an upper contact S to a lower one 8¹.
When a sudden danger arises e.g. fire or the like the alarm may be given
in all the rooms simultaneously as it is possible to short circuit all the contacts 8
& 8 simultaneously. For this purpose the lower row of contacts 8¹ is movable
and slides up and down in guides 9. Moreover there is a sliding contact bar 10
in the guides, insulated from the row of contacts 8', which bar under ordinary
circumstances is insulated from the lower row of contacts 8¹. A lever 12
provided with a friction-roller 11, which is put in connection with the current
clamp 13 by a special wire, when moved in the direction of the arrow raises the
contacts 10 and also the contacts 8¹ and presses them against the upper row of
contacts 8. Simultaneously the whole current from the clamp 13 and the lever 12
passes into all the contacts, where it divides and rings the alarms in all the
rooms.
The bells in the several rooms are in connection with one pole of the battery,

page_text: while the other pole of the battery goes to the clamp 13. Thence the current
passes either through the clockwork, through the several contacts 8 & 8 back
to the bell or through the lever 12 according to the way in which the contrivance
is used.
The construction of the several contacts, cords &c. as well as insignificant
structural details has no influence on the essential part of the invention.
In order to apply the invention described above to the purpose of indicating
the times for beginning and ending work in factories, the switch-board illustrated
in Figure 5 is most advantageously employed. On it there are 12 (or 24) upper
contacts for (or 4) hours (vide No. and 1 of the drawing) and 12 (or 24)
lower contacts for full hours (or hours) (see No. 2 & 2) No. 3 & 31 are contact
springs between which the lever 5 is supported: this lever is movably attached
át 4 in such a way that it may be held up by the catch 6 when
not in use. The method of operation is as
follows:
rooms.
From the
battery the current passes through the contact 13 to the clock, i.e.
to the contact-strip 4 (wide Fig. 2 & 3) and successively by the contact-
springs 3 through the wires 4', which are continued from the latter (3) to the
different factory-rooms successively or repeatedly to be advertised according to
the position of the pins on the disc 2 and joined to the bells established in these
From the bells the wires 41 are led to the contacts 1,
11, 2 and 2 and then the current is communicated through the connection cords 7
to the springs 3 & 3 and returns through the lever 5 and the joint 4 back to the
battery. In the illustration the times given illustratively are 7 o'clock 9, 10.30,
12, 2.30, 4, 5.30 and 7, but all times can be arranged as desired. In factories
working day and night shifts a disc with 48 contacts is substituted in the clock
for the disc 2. The intervals may also be hours so that the invention may be of
practical and easy application in factories, hospitals, barracks, charitable institu-
tions &c. For Saturdays and Sundays when the working times are altered accord-
ing to requirements a switch board can be used so that then only the levers are
used. When at rest the lever 5 is turned up.
Having now particularly described and ascertained the nature of our said
invention & in what manner the same is to be performed we declare that what
we claim is―
CLAIMS.
First An electric central alarm, characterised by a disc (2) supporting contact
pins arranged helically or otherwise attached to the hour-wheel-arbor of a suitably
constructed clock, which disc raises and presses against a contact strip (4) the
contact springs (3) fixed at suitable distances apart, whereby, through the medium
of a connecting link, such as the connecting cords (7 & 7¹) and the contacts (5, 8
and 8¹) one or more bells in different rooms are made to ring.
Second In a contrivance as described in Claim 1 the connection of the
current clamp (13) by a special wire with the lever 12 and the arrangement that
through this lever (12) a movable contact (10) as well as the lower row of
contacts (8) may be moved up in guides in order that they may all be connected
for the purpose of ringing the alarms in all the rooms simultaneously in case
of fire or any similar danger.
Third: In the contrivance described in Claim 1 the introduction of a switch-
board provided with contacts corresponding to the requisite times for work.
Dated this 3rd day of February 1899.
JOHANN WILHELM HERMANN WENDT,
KARL LUDWIG KRAUSSE,
By George Barker,
Fellow of The Chartered Institute of Patent Agents,
Agent for Applicants, 77, Colmore Row, Birmingham.