Improvements in Electric Bell Indicators.
Year: 1891

page_text: Date of Application, 30th Oct., 1891
Complete Specification Left, 28th July, 1892-Accepted, 3rd Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Electric Bell Indicators.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, West-
minster in the County of Middlesex, GEORGE SYLVESTER GRIMSTON, of
Claremont, Glenluce Road, Westcombe Park, and ERNEST PERRETT, of
33 London Street, Greenwich in the County of Kent, Electrical Engineers, do
hereby declare the nature of this invention to be as follows :-
-
Usually a number of screens, marked with numerals or otherwise distinguished,
are arranged on a board or on a wall, each screen being actuated electrically so as
to present itself visibly for the purpose of indicating, when a bell or gong is
sounded, the particular apartment or place whence the electrical call has come.
It is often difficult to distinguish these indicators unless they are, well lighted and
observed from a position almost directly in front of the indicator board. Moreover,
the gear consisting of an electro magnet, a detent and a spring by which each of the
indicators is actuated, being more or less exposed, is liable to become oxidised,
especially at sea, and affected by dust and dirt so that its action is often seriously
interfered with. Further wherever the apparatus is subject to oscillation, as for
instance at sea, the indicators are liable to become released when they should not
be so.
The object of this invention is a construction of electric bell indicators such that
they are readily distinguishable even when viewed obliquely, and that their
actuating gear is protected against dust, damp or other external damaging
influences, and against oscillatory shocks. For this purpose, we make each
indicator in the form of a hollow sphere or cylinder, which may be of thin sheet
metal or other light material, and which is mounted so that it can turn about half
round a stationary axis presenting always about half its body beyond the face of
the board. Within it is fixed on the axis an electro magnet the coil of which is
connected at one end to the return circuit through the metal of the apparatus and
at the other end by an insulated wire to the conductor from the apartment or place
to which this particular indicator is appropriated. A spring urges the indicator to
turn round its axis, but in its normal position it is prevented from turning by a
detent connected to the armature of the electro magnet. When the armature is
attracted the detent is released and the indicator makes a half turn, and the half
then visible beyond the board being coloured or otherwise marked so as to
distinguish it from the face of the board and from the visible halves of the other
indicators, can be readily seen by an attendant even when he looks obliquely
towards the board.
The attendant can afterwards turn the indicator back by hand, whereupon the
detent becomes again engaged and holds the indicator in its normal position
presenting outside the board that half of its body which is not coloured or otherwise
distinctively marked.
In order to turn the indicator back to its normal position, it has a pin projecting
from some part of its circumference to which the attendant can apply his fingers
directly; but, in order to facilitate the turning back of any one of a number of
indicators, there is provided behind the board for each line of indicators a rod
connecting a crank at the one end to a crank at the other end of the line, these
cranks being mounted axial with the indicators. The attendant, by turning the
crank half round, causes the rod to sweep half round the line of indicators and if
any one of them has been released, the rod meeting its projecting pin carries it
round until its detent becomes engaged in its normal position.
Each line of indicators may have its cranks worked separately by hand, or the

page_text: cranks of two or more of the lines may be connected by suitable gear so that they
are simultaneously turned when one is turned.
Dated this 30th day of October 1891.
ABEL & IMKAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Electric Bell Indicators.
We, SIEMENS BROTHERS & Co. LIMITED, of 12, Queen Anne's Gate, West-
minster in the County of Middlesex, GEORGE SYLVESTER GRIMSTON, of
Claremont, Glenluce Road, Westcombe Park, and ERNEST PERRETT, of
33, London Street, Greenwich, in the County of Kent, Electrical Engineers, 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:-
Usually a number of screens marked with numerals or otherwise distinguished,
are arranged on a board or on a wall, each screen being actuated electrically so as
to present itself visibly for the purpose of indicating, when a bell or gong is
sounded, the particular apartment or place whence the electrical call has come. It
is often difficult to distinguish these indicators unless they are well lighted and
observed from a position almost directly in front of the indicator board. Moreover,
the gear consisting of an electromagnet, a detent and a spring by which each of the
indicators is actuated, being more or less exposed, is liable to become oxidised,
especially at sea, and affected by dust and dirt so that its action is often seriously
interfered with. Further whenever the apparatus is subject to oscillation, as for
instance at sea the indicators are liable to become released when they should not
be so.
The object of this invention is a construction of electric bell indicators such that
they are readily distinguishable even when viewed obliquely, and that their
actuating gear is protected against dust damp or other external damaging
influences and against oscillatory shocks. For this purpose, we make each
indicator in the form of a hollow sphere or cylinder, which may be of thin sheet
metal or other light material, and which is mounted so that it can turn about half
round a stationary axis, presenting always about half its body beyond the face of
the board. Within it is fixed on the axis an electromagnet the coil of which is
connected at one end to the return circuit through the metal of the apparatus and
at the other end by an insulated wire to the conductor from the apartment or place
to which this particular indicator is appropriated. A spring urges the indicator
to turn round it axis, but in its normal position it is prevented from turning by a
detent connected to the armature of the electromagnet. When the armature is
attracted the detent is released and the indicator makes a half turn and the half
then visible beyond the board being coloured or otherwise marked so as to
distinguish it from the face of the board and from the visible halves of the other
indicators, can be readily seen by an attendant even when he looks obliquely
towards the board.
The attendant can afterwards turn the indicator back by hand, whereupon the
detent becomes again engaged and holds the indicator in its normal position
presenting outside the board that half of its body which is not coloured or otherwise
distinctively marked.
In order to turn the indicator back to its normal position, it has a pin projecting
from some part of its circumference to which the attendant can apply his fingers
directly; but, in order to facilitate the turning back of any one of a number of
indicators, there is provided behind the board for each line of indicators a rod
connecting a crank at the one end to a crank at the other end of the line, these
cranks being mounted axial with the indicators. The attendant, by turning the

page_text: crank half round, causes the rod to sweep half round the line of indicators and if
any one of them has been released, the rod meeting its projecting pin carries it
round until its detent becomes engaged in its normal position.
Each line of indicators may have its cranks worked separately by hand, or the
cranks of two or more of the lines may be connected by suitable gear so that they
are simultaneously turned when one is turned.
The accompanying drawing is a vertical section of the case containing a number
of bell indicators according to this invention. They are here shewn as four
horizontal rows in height, and each row may contain any required number. There
may be a glass front G to the case, behind this is a screen S having circular holes
through it, one for each of the indicators I which consists of a spherical casing
partly projecting beyond the screen S. One of the indicators is shewn in section.
Within the casing I is fixed on a stationary central spindle the electro magnet M
consisting of a soft iron tubular core within a bobbin wound with insulated wire.
To the lower end of the bobbin is pivotted an armature lever A which at the
farther end is formed as a hook catching a catch i projecting inwardly from the
spherical casing I. To this catch is attached one end of a volute spring B
the other end of which is fixed to the central spindle. From the exterior of the
spherical casing projects a stud C. On pivots in the same axial line with the central
spindles of the indicator is mounted a long crank D extending the whole height of
the column of indicators, which can be turned by a knob E.
When the electromagnet in one of the indicators is excited by a current as above
described, it attracts its armature releasing the catch i and thereupon the spring B
causes the indicator to turn about half round till its outwardly projecting stud meets
the crank D. The attendant readily seeing which indicator has turned (the colour
of the half presented being different from that of the screen S) resets it by turning
half round the crank D until the armature lever again engages the catch i.
Obviously if several of the indicators in the column have been turned, the movement
of the crank D can reset them simultaneously. The crank D for each column
may be worked by a separate knob E, or the cranks D for all the columns may be
linked together, so that they are all turned simultaneously by means of one knob E,
thus resetting any of the whole number of indicators. The casing of each indicator,
instead of being spherical, may be cylindrical, in which case the holes through the
screen S are rectangular.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An electric bell indicator having an electromagnet, armature spring and catch
enclosed within a spherical or cylindrical casing of which part projects visibly
through a screen, substantially as described.
2. In combination with a number of indicators such as are above referred to,
cranks arranged to act on studs projecting from the indicators so as to reset them
after they have moved, substantially as herein described.
Dated this 28th day of July 1892.
ABEL & IMRAY,
Agents for the Applicants.