Improvements in and connected with Electric Bells.
Year: 1898

page_text: Date of Application, 7th Apr., 1898
Complete Specification Left, 13th Dec., 1898-Accepted, 18th Mar., 1899
PROVISIONAL SPECIFICATION.
Improvements in and connected with Electric Bells.
I, HERMANN OPPENHEIMER, Electrical Engineer, of 55, Redcross Street, Barbican,
London, E.C., do hereby declare the nature of this invention to be as follows:-
In electric bells, which are used in mines, chemical works, dye works).
breweries, etc., it is essential to protect the movements against the influence of
moisture or of explosive gases. The greatest difficulty has been experienced in.
stuffing the opening in the cover through which the hammer of the bell protrudes.
As I show on the accompanying drawing, the to and fro movement of the hammer
which generally necessitates an opening in the cover, is here replaced by the
revolving movement of the axis A, which is put vertically to armature K and
hammer stem H by which both are joined. Such opening with pivot can easily be
stuffed without requiring a larger amount of power for actuating the latter.
In most cases it will suffice to apply to the pivot some grooves into which some
fatty material is put, or which are filled up by means of paraffined cords. In
large apparatus, however, more especially in those which should be gas-proof, it
will be necessary to provide suitable stuffing boxes as shown in Fig. 3.
Furthermore, the cover D is grooved out at its lower part which fits to the back-
board, and between the backboard and such grooved-out rim of the cover D, there
is laid paraffined cord S, which is firmly pressed against the backboard when the
cover is screwed down, thus excluding water or moisture from the movement.
For the terminals L, L; I provide a separate cast iron cover G, which allows
of introducing the line wires through side holes, and such terminals have connec-
tion with the interior of the bell movement. After the line wires have been
properly connected to the terminals, the cast iron cover G is filled with paraffin
or pitch, and covered with cover D, thus being made absolutely water-tight.
The construction of this bell is not very different to what I describe in my
Patent No. 7492/1892, but it has some further points, which show certain improve-
ments.
The electro-magnet with its poles is directed downwards, whereby the hammer
is properly balanced through the armature.
To pull the armature K from the poles, I employ a spiral spring F and a contact
pillar U which with its grooved part V is fixed to metal strip M, the latter being
insulated by means of ebonite bushes and washers from the cast iron backboard.
To suit a differently shaped cover, or in order to place the dome in a different
position, one may use a deeper or a broader cover of comparatively smaller height,
whereby the electro-magnets can be fitted flat, or in a different position to what
I describe above.
In such case the pivot connecting armature and hammer stem can, instead of
protruding through the backboard, be arranged to pass through the side wall of
the cover, or instead of making the front of the cover moveable, either of the
2 side walls may be made available for such purpose.
Dated this Sixth day of April 1898.

page_text: improvements in anu connected with ElectTIC DULIS.
I, HERMANN OPPENHEIMER, Electrical Engineer, of 55, Redcross Street, Barbican,
in the City of London, 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: —
In electric bells which are used in mines, chemical works, dye works,
breweries, etc., it is essential to protect the movements against the influence of
the moisture or of explosive gases. The greatest difficulty has been experienced in
stuffing the opening in the cover through which the hammer of the bell protrudes.
As I show on the drawing accompanying the Provisional Specification the to
and fro movement of the hammer which generally necessitates an opening in the
cover, is here replaced by the revolving movement of the axis A which is put
vertically to armature K. and hammer stem H by which both are joined. Such
opening with pivot can easily be stuffed without requiring a larger amount of
power for actuating the latter.
In most cases it will suffice to apply to the pivot some grooves into which some
fatty material is put, or which are filled up by means of paraffined cords. In
large apparatus however, more especially in those which should be gas-proof, it
will be necessary to provide suitable stuffing boxes as shown in Fig. 3.
Furthermore, the cover D is grooved out at its lower part which fits to the back-
board, and between the backboard and such grooved-out rim of the cover D, there
is laid paraffined cord S, which is firmly pressed against the backboard when the
cover is screwed down, thus excluding water or moisture from the movement.
For the terminals L, L, I provide a separate cast iron cover G, which allows
of introducing the line wires through side holes, and such terminals have connec-
tion with the interior of the bell movement. After the line wires have been
connected to the terminals, cast iron cover G is filled with paraffin or pitch, and
covered with cover d, thus being made absolutely water-tight.
The construction of this bell is not very different to what I describe in my
Patent No. 7492/1892, but it has some further points which show certain improve-
ments.
The electro-magnet with its poles is directed downwards whereby the hammer
is properly balanced through the armature.
To pull the armature K from the poles, I employ a spiral spring F and contact-
pillar U which with its grooved part V is fixed to metal strip M, the latter being
insulated by means of ebonite bushes and washers from the cast iron backboard.
To suit a differently shaped cover, or in order to place the dome in a different
position, one may use a deeper or a broader cover of comparatively smaller height,
whereby the electro-magnets can be fitted flat, or in a different position to what
I describe above.
In such case the pivot connecting armature and hammer stem, can instead of
protruding through the backboard, be arranged to pass through the side wall of
the cover, or instead of making the front of the cover moveable, either of the
2 side walls may be made available for such purpose.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is;-
1. An electric bell with water and air tight cover, arranged in such a manner
that the armature of the electro-magnet by means of a pivot, which latter connects

page_text: the armature with the hammer stem, is protruding through a wall of the cover,
and the opening of which has either a stuffing box, or is suitably lined, substan-
tially as and for the purpose specified.
2. An arrangement of the terminals of such bell in a cast iron box, with suitable
holes, which, after the line wires have been introduced can be filled up with paraffin
pitch or other insulating material, substantially as and for the purpose specified.
Dated this 2nd day of December 1898.
'
HERMANN OPPENHEIMER.