Improvements in Electric Switches.
Year: 1899

page_text: Date of Application, 2nd Feb., 1899-Accepted, 25th Mar., 1899
Improvements in Electric Switches.
I, CARL FÜRER, M.D., of Hans Rockenau, near Eberbach, in the Empire of
Germany, 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 subject of the present invention is an apparatus for closing and interrupt-
ing electric currents, which is applicable to all descriptions, strengths, and
tensions of such currents; and which is more especially applicable for use in
dry, dusty, and damp rooms; and in such rooms as contain vapours which corrode
metals.
The main characteristic of the invention is that the metal etcetera, parts are in
the nature of springs, which effect the closing and/or interruption of the circuit,
as the case may be, and the construction of which varies according to the
respective purposes, and are placed in a casing of some elastic material, which
casing is let into a base, proof against water, etcetera, of an absolute close kind.
By pressing upon the elastic casing, the contact is made or broken, as the case
may be. The form of the elastic casing, and the material upon which the appar-
atus is mounted, as well as the substance which is cast round the parts for
obtaining a hermetical closure, may vary, according to circumstances.
The applicability of the apparatus constructed as described is universal. By
means of it, it is both possible to effect a contact which will exist as long as the
pressure acts which produces it, and at the ceasing of which the circuit opens of
its own accord. Or, by means of a modified corresponding construction, by one
pressure, the circuit may be closed for any desired length of time, and by a
second pressing it is opened again.
For apparatus for closing and interrupting strong currents, according to this
invention, the arrangement is so made that a double lever is employed which
in the case of light circuits, for instance, for single lamps, consists of some
insulating solid material, carrying at one end the connecting, and at the other,
the disconnecting button, and also a thin, wedge-shaped insulating tongue,
which in one action is pressed between the contact springs which touch each
other, and in the other, is drawn out from between them.
In the case of circuits for currents of great strength, the usual construction
of contact is used for the springy metal parts, which are at a distance from
each other, and between which the metal wedge, carried by the double lever, is
in one act inserted, and in the other withdrawn.
If simple pressure, by means of the fingers is not sufficient, then the pressure
on the elastic casing may be effected indirectly, by means of levers arranged on
the outside, or by other suitable means.
In the annexed drawing, two arrangements or modifications are given.
Figure 1 shews an apparatus suitable for ringing appliances and the like, as
seen from above; and Figures 2 and 2* are sections of same.

page_text: Figures 3, 4, 5 and 6, shew a view from above and sections of a construction
suitable for use in light installations, and the like.
With reference first to the arrangement shewn in Figures 1, 2, and 24, 1 the
apparatus comprises two appropriately bent springs a and b, with which the
circuit wires c and d are connected. The springs should be so placed that in
the act of making the contact, a firm resistance is offered to the pressure; the
lower spring should, therefore, be supported, either by allowing it to rest directly
upon the base of the apparatus (see Figure 2^), or by supporting it by means of
a pin (see Figure 2). The whole arrangement is enclosed in a casing k made
of some elastic material-celluloid, etcetera. is suitable-which is let into an
appropriately deep groover in the base m. The groover, after the casing has
been inserted is filled by means of a substance (such as paraffin wax, etcetera)
which will close the whole hermetically to outside influence. The wires are
brought to the springs through the base through holes, which likewise would
be closed again hermetically.
By pressing on the easing k, it will take the position shewn in dotted lines
in Figures 2 and 24, and effect a contact between the springs a and b, and thus
the circuit will be closed. If suitably made, the pressure required to effect
the contact need be only infinitesimal. By this construction, the springs may
be placed at an infinitesimal distance from each other, as there need be no fear
of defective contact by reason of the intrusion of dust, moisture, etcetera.
In the case of the arrangement or modification shewn in Figures 3 to 6, which,
as previously mentioned, is intended for installations in which strong currents
are employed, and such where it is a question of breaking or opening circuits
which have been closed and existing for some time, a double lever is used,
made of one piece of solid non-conducting material, such as bone, etcetera. This
lever at both its ends carries buttons 71 73, and close to one of same is a narrow
tongue, the upper end of which is wedge shaped. It (the lever) is let into a
groove in the piece of material m, which carries the whole apparatus; and it
turns round a pin 7 fastened across the groove, so that it can be pressed up and
down. At the point where the tongue lies, the contact springs y y¹ are so
fixed at the sides of the grooves, that by pressing the button p² the tongue
enters between the springs which touch each other, whereby they are separated
and the contact is broken, the tongue being at the same time held firmly
-between the springs. By pressing the button p¹, the tongue is withdrawn from
between the springs, and the contact is re-made. For strong currents the
arrangement is so made that the contact springs are fastened at an appropriate
distance from each other (see Figure 6); and in the place of the insulating
tongue, the double lever, made of suitable material, carries a conducting metal
wedge (A), the insertion of which between the springs makes the circuit, and vice
versa. The entire making or breaking mechanism is enclosed in a casing t made
of elastic material (such as celluloid, etcetera) which is let into and fastened in
the groover in the base, as above described; but in such a way that either of
buttons on the lever can be depressed by pressure on the casing at the right
point. The hermetical closing of the whole, including the wires, is effected in
the same manner as in the former instance.
'
Having now particularly described and ascertained the nature of this
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. Apparatus for closing and breaking or opening electric circuits, comprising
a contact device or mechanism, and an elastic casing over and enclosing same;
adapted to act substantially as and for the purposes set forth.
2. In apparatus for closing and breaking or opening electric circuits, a lever
adapted to be operated about its fulcrum at either end; a contact or making
and breaking part on said lever; and an elastic casing over and enclosing the

page_text: mechanism through which said lever is adapted to be operated; substantially as
and for the purposes set forth.
3. The electric circuit closing and breaking or opening apparatus shewn in
and set forth with reference to Figures 2, and 2*; and Figures 3, 4, 5, and 6,
respectively of the drawings.
Dated
THIS
Curuary
CARL FÜRER,
By Cheesbrough & Royston,
Applicant's Patent Agents, 15, Water Street, Liverpool.