Improvements in a Self-restoring Annunciator more particularly suitable for Employment in connection with Telephone Switch- Boards.
Year: 1898

page_text: Date of Application, 9th Feb., 1898-Accepted, 4th June, 1898
COMPLETE SPECIFICATION.
Improvements in a Self-restoring Annunciator more particularly
suitable for Employment in connection with Telephone Switch-
Boards.
I, JOHN EDWARD KINGSBURY, of 79, Coleman Street, in the City of London,
Manager, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by THE WESTERN ELECTRIC COMPANY of Chicago,
Illinois, United States of Ameria), and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to provide an annunciator which shall be sensitive
in operation, while the mechanical construction is such that the annunciator may
be readily removed for repairs or adjustment and may be made at a minimum
cost.
The usual annunciator casing enclosing the core and the actuating coil of the
annunciator is supported at each end in a perforated plate.
The two plates are held at a constant distance by supports placed at intervals
and a number of drops may be mounted upon one set of plates.
All of the parts of the drop are mounted integral therewith and are independent
of the supporting plate so that the drops may be readily removed from the latter
for adjustment or repairs. The armature is mounted upon the rear end of the
casing of the drop and carries the lever or rod which extends through an enlarge-
ment of the opening in the supporting plates. The rod has at its end a hook
which is adapted to engage and retain the annunciator drop in its elevated
position.
Mounted upon the front of the drop casing and projecting perpendicularly
therefrom are provided a pair of extensions constituting a part of the magnetic
circuit of the restoring coil. The central core also projects beyond the coil.
The outside extensions are provided in their ends with slots in which pins
carried upon the annunciator shutter are adapted to rest, the slots serving as
bearings in which the pins may turn. The pins are maintained in the slots
and end-motion is prevented by means of screws passing into the end of the
cores.
"
The annunciator shutter carries a retaining arm adapted to be engaged by
the hook upon the longitudinal arm or lever carried upon the annunciator
armature.
A block of insulating material is mounted upon the rear end of the drop casing
at some distance therefrom and the drop armature is arranged to oscillate between
this and the casing. The armature is suspended by means of wire pins resting
in slots in the drop casing. These wire pins are held in place by screws in similar
manner to that employed in the suspension shutter. The insulating block carries

page_text: an adjustable contact screw which acts as a rear stop for the armature after the
shutter has been released and at the same time it closes a night-bell or other
circuit. When the shutter is held by the catch of the armature lever, the
armature does not touch the contact screw. This insulating block also carries
the terminals of the coils. The shutter comprises an armature consisting of 2
cylinders of magnetic material, the target of the drop and the retaining arm, the
cylinders of the armature being adapted to lie in a position more or less parallel
with the core extensions of the restoring coil, the armature moving into an
angular position due to its own weight when the drop is released. Upon closing
the circuit, by means of the plug or other apparatus used in connection with
the annunciator, through the coil of the auxiliary restoring electro magnet the
armature is moved into a position to restore the shutter due to a tendency of
the lines of force to shorten their path through the armature. By placing the
number to be brought to view on a different part of the same mechanism it can
be displayed by current in the auxiliary coil and be made to disappear by gravity
as has been done in a number of visual signals heretofore. In this case the main
coil acts upon the armature so as to close the necessary relay contacts so that
I have a visual signal and its relay mounted in one casing.
In the following description reference is made to the following drawings:
Figure 1 is a view in elevation of the annunciator, the shutter armature being
shown in its elevated position with the target in an undisplayed position.
Figure 2 is a plan view of the annunciator.
•
Figure 3 is a sectional view with the shutter in the normal position.
Figure 4 is a sectional view on a horizontal plane.
Figure 5 is a view of the rear of drop showing the armature and the insulating
block carrying the night-bell contacts and the coil terminals.
Figure 6 is a front view of the drop showing the shutter in its undisplayed
position.
Figure 7 shows the drop in a position partially removed from its supporting
frame.
Figures 8 and 9 show the shutter and the drop in its normal and displayed
position respectively.
Figure 10 and 1Ì show a different arrangement of shutter parts in a displayed
and restored position.
Figures 12 and 13 show arrangements of the shutter parts adapted to make the
number visible upon circulation of current in the auxiliary coil, the shutter being
restored to its normal position by gravity. Figure 12 shows normal position,
Figure 13 shows displayed position.
Figures 14 and 15 are views of different arrangements of shutter parts in
which the number is made visible by circulation of current in the auxiliary coil
and is made to disappear from view by gravity.
Like parts are similarly lettered in the various drawings.
The supporting frame consists of the two plates a and a¹ of a convenient
length to receive the number of drops intended to be held in one frame, these
plates are held parallel at a convenient distance from one another by means of the
distance pieces 6.61 fastened to the plates at suitable intervals. The plates have
openings cc for each drop through which the drop proper is adapted to be
inserted either from the front or the rear side of the strip.
The drawings show the method of insertion and removal from the rear, but
slight modifications of the rear part of the drop will allow of its being inserted
from the front.
The drop is fastened to the frame by means of screws & d¹.
The drop proper
consists of the two electromagnets f and g their coils and their magnetic circuits.
The central core e is common to both coils, the two coils f and g being separated
by the ring of magnetic material h. The core with the coils is enclosed in the
slotted tube i of magnetic material. The central core projects beyond the en-
closing tube a certain distance at each end. To each end of the core the

page_text: rings of non-magnetic metal kk¹ are securely fastened so as to firmly hold in
place the two coils and the intermediate ring of magnetic material. The
rings kk each have a shoulder on them so as to receive the rings 7, 11, of magnetic
material. The ring carries the two projecting pole pieces m m² of the restoring
coil magnetic circuit, whereas the magnetic circuit of the main coil f is continued
to the armature n by means of the screws o o¹ of magnetic material. These two
screws also fasten the metal piece p in which the armature n is hung and to which
the insulating block is fastened. The insulating block carries the four
terminals of the coils, the wires which make connection between the terminals
and the coils being imbedded in the slot of the outside casing. The block also
carries the insulated contact screw r, which serves both as a stop limiting the
motion of the armature n and, in connection with a contact on the armature
proper, can be used to close an electrical circuit. The armaturen has a forward
extension n fitted with a catch at its outer extremity adapted to engage the
retaining arms of the shutter t. In connection with the retaining arm there are
provided the pins u u¹ arranged to rest in the slots of the outside projecting
cores m m of the magnetic circuit of the restoring coil. Screws ¹ limit
the side motion of the pins resting in the slot and hold them in place and also
serve to fasten the plate which may in certain cases carry the number to be
displayed. To the retaining arm of the shutter there are also fastened two
short cylindrical armature pieces y y¹ at such a distance as to fit into the space
between the extension of the central core e and the outside core extensions m m¹
of the restoring coil.
These armature pieces and the retaining arm may be so arranged with respect to
the shutter as to cause a displayed number to disappear from view when current
circulates in the restoring coil g. In this case the armature pieces y y¹ assume
a position more or less parallel with the core extension e and extensions m m¹
bringing the shutter into its normal position.
It is then held by the catch of armature lever n¹ and can again be released and
the number brought to view by the action of the armature n after the cessation
of current in the restoring coil g.
The
In other cases it may be desirable to display a number by the action of current
in the restoring coil. The number to be displayed is then so arranged that it is
visible during the active condition of the restoring coil and is covered over or hid
from view by the action of gravity upon cessation of current in the coil.
displaying circuit can in this case be closed by the action of the main coil after
the latter has been fitted in any of the well known ways with the necessary
contacts so as to act as a relay.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. The combination of an annunciator drop with perforated parallel plates
supporting the drop at each end.
2. In a self restoring annunciator drop the combination of a suspended main
coil armature with a rear stop insulated from the body of the drop and adapted
to make contact therewith after the release of the shutter by the catch of the afore-
said armature.
3. An annunciator drop in which the armature or shutter is hung by pins
attached to the armature or shutter resting in slots in projecting supports, into
the ends of which supports screws are inserted to hold the pins in the slots and
prevent end motion of the pins.
4. An electromagnet having projecting pole pieces, to which pole pieces an arma-
ture is pivotally attached so that when the electromagnet is energised the armature
will be drawn between the polar extensions.

page_text: 5. In a self-restoring annunciator drop the lodging of the wires connecting the
coils with their terminals, in a slot in the metal containing tube.
6. Self-restoring annunciators substantially as described and shown in the
drawings.
Dated L
011
1
1000