An Electric Switch.
Year: 1899

page_text: Date of Application, 31st Jan., 1899-Accepted, 23rd Sept.,
1899
An Electric Switch.
I, MARTIN SCHMIDT, Engine Fitter, of 29, Humboldtstrasse, Bochum, 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:-
This invention for an electric switch relates to a switch more especially adapted
for use in damp places or places filled with corroding gases and which can be
used without the internal mechanism being injured or rendered unserviceable, as
would be the case with the ordinary apparatus employed for the purpose, if so
placed.
Fig. 1 is a section of the switch.
Fig. 2 a plan of the same.
Fig. 3 a section along the line x-x in Fig. 1.
Fig. 4 a similar section with inserted central contact piece.
Fig. 5 is a similar section showing the complete internal mechanism.
Fig. 6 is a front elevation of the switch.
Fig. 7 is a similar view showing the switch mounted on an insulator.
Fig. 8 the handle of the switch in section through y-y Fig. 9 and on an
enlarged scale.
Fig. 9 is a horizontal section through x-x Fig. 8.
The switch comprises the casing a which is of porcelain or other suitable
material, and furnished at the sides with the openings 66' for the insertion of
the wires. On the bottom of the casing are three perforated feet dd'd¹¹ for
fixing the apparatus. Inside the casing several semi-circular pieces cc are pro-
vided. These pieces correspond with similar incisions in the bed-plate and are
intended to render any displacement of the bed-plate impossible.
The openings 6 6¹ are preferably filled in with some suitable material after the
laying of the wires, so that it is impossible for any damp to penentrate into the
interior of the casing.
The casing a is closed by means of the cover which is of similar material, a
Packing ring f being inserted between the two, so that from this side also the
entrance of damp air or corroding gas is rendered impossible. On the bottom of
the casing and inside the same is the bed-plate 9 of insulating material, on
which the switch apparatus is mounted. Between the bed-plate and the bottom
of the casing is an india-rubber disc f¹ serving to prevent any compression of the
bed-plate. In order that the bed-plate may be held firmly on the bottom of the
casing, a porcelain ring his provided on which bears a screw ring i, screwed into
the interior of the casing.
A supporting piece k carrying springs e e¹ is fixed on the bed-plate by means
The heads of the
of four screws passing from below through the bed-plate.
The springs eel screwed on to the
screws are suitably let in and covered over.
support k are composed of several thin steel, brass, or copper plates, in order to
secure better spring action, and are intended to operate on a block m which is of

page_text: square section and shown in Fig. 4, and cause it to take up a determinate posi-
tion in which the circuit is either opened or closed. The block m consists of two
parts insulated from each other. In the middle of the bed-plate g or in other
words of the perforated. contact holder k is the rotary spindle A, to which the
divided square-section block m is fixed. Likewise on the spindle A, directly
above the block m, is fixed the spring n, composed of several thin strips of copper,
the purpose of which is to establish connection between the contact pieces o
and o, that is, to close or open the circuit. These contact pieces o and o¹ are
likewise fastened to the bed-plate from below by means of screws and are in
conductive" connection with the wires either by binding screws or soldering.
Between the pressing ring hand the screw ring i is a packing ring f" and a
tinned metal plate q, in the middle of which plate is a stuffing box for the pack-
ing and passage of the spindle A. In case of necessity, a packing and insulating
material may be laid on to the plate q. On the projecting end of the spindle A
is the handles which is of horn, vulcanite or other suitable material.
66
In order to prevent the bright metallic parts from coming into contact with
the external air, the fastening nut v is let into the handle and covered by a screw
closing plate w of the same material as the handle. As will be seen from Fig. 8,
in the handles is a brass piece n, with a side nose-piece or projection u¹, and
which is fixed into the handle by means of two pins y, and rotates loosely on the
spindle A. The circular piece z, which is firmly scated on the spindle A, is
furnished with additional pieces or projections 2¹ against which the nose-piece u¹
on the brass piece n strikes.
In operation the movement of the switch s is transmitted to the spindle A by
the projections u¹¹ till the corners of the block m come against the springs e e¹
and on rotating the spindle a little further by hand, the springs eel operate on
the block to complete the movement. It is obvious from the foregoing that the
contact springs n attached to the spindle will come against and be removed from
the contact pieces o o' with accelerated quickness. As this action takes place
suddenly sparking will not take place, when the switch is moved to cut the
current on or off, or when one of the contacts should melt or burn.
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:-
1. An electric switch for use in damp places, the distinguishing feature of
which is the arrangement of a switching apparatus in a casing a capable of being
made air tight, the conducting wires being inserted through openings 66¹ which
can be filled in.
2. In a switch as described under Claim 1, the arrangement in the air-tight
closing casing of a plate q furnished in the middle with a stuffing box r for the
purpose of impermeably closing the switch apparatus.
3. The improved electrical switch substantially as described with reference to
the drawings.
Dated this 31st day of T
1000
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.