Year: 1886

page_text: Date of Application, 4th Oct., 1886.
Complete Left, 29th June, 1887.
Complete Accepted, 29th July, 1887.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention to be as follows :-
--
In a telegraphic relay, the same tension of the spring, provided for keeping the
armature off the poles of the electro-magnet, is not equally well adapted both for
strong and feeble currents actuating the relay. If the spring be weak, strong currents
may cause the armature to adhere to the poles of the electro-magnet even after the
line circuit has been broken, and on the other hand, if the spring be strong, feeble
currents may be unable to overcome it.
The object of this invention, is to obviate this objection which is effected by means
of the following arrangement. The arm of the armature lever, carrying the armature
and adapted to close the local circuit by touching a contact-screw, is made of a flexible
plate spring or of a jointed bar, which is maintained in a stretched condition by means
of springs or weights, and the relative arrangement of the said contact-screw, and the
poles of the electro-magnet, is such as to allow the armature-lever to touch the said
contact-screw and thereby to close the local circuit before the armature touches the
poles of the electro-magnet.
In combination with this flexible armature lever is an arrangement whereby an
auxiliary antagonistic spring is brought into action when the line circuit is broken,
the office of this spring being to overcome the residual magnetism.
When the electro-magnet is actuated by feeble currents, the armature will be arrested
as soon as soon as its lever meets the contact-screw, as the magnetic force of the
electro-magnet will not be sufficient to curve the flexible arm of the armature-lever,

page_text: so as to approach the armature closely to the poles, but, strong currents will cause the
armature to be fully attracted, and during the last portion of its motion, viz:-from
the moment when the armature-lever has met the contact-screw, the auxiliary spring
comes into play. This may be effected by the armature carrying along with it, the
end of a lever and so putting in tension either the antagonistic spring of the armature
lever, or any other oposing spring, so that as soon as the line circuit is broken a spring
of sufficient force to overcome the residual magnetism, will be brought into action.
Dated this 4th day of October 1886.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Telegraphic Relays.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53, Chancery
Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents, do
hereby declare the nature of this Invention (a communication to me from abroad by
Carl Diener of Vienna, in the Empire of Austria Manufacturer), and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :-
It is well known that in a telegraphic relay, the same tension of the spring, provided
for keeping the armature off the poles of the electro-magnet, is not equally well adapted
for both strong and feeble currents actuating the relay. If the tension of the spring
be weak, strong currents may cause the armature to adhere to the poles of the electro-
magnet even after the line circuit has been broken, and on the other hand, if the tension
of the spring be strong, feeble currents may be unable to overcome it.
Now the present invention has for its object to provide means for the automatic
adjustment of the tension of the said armature spring.
For this purpose the arm of the armature lever, carrying the armature and the
contact piece by which the local circuit is closed, is made of a flexible plate spring (or
of a spring jointed bar) and the contact screw corresponding to the said contact piece
is arranged in such position with respect to the poles of the electro-magnet, that when
the armature is attracted, the contact piece of the armature-lever will touch the
corresponding contact-screw and thereby close the local circuit, before the armature
touches the poles of the electro-magnet. In consequence of this arrangement the
armature will only be caused to touch the poles of the electro-magnet when the latter

page_text: is influenced by strong currents, as weak currents will not produce a magnetic force
sufficient to inflect the plate spring which carries the armature. In order to increase
the tension of the armature spring when the electro-magnet of the relay is actuated
by strong currents, a lever is provided which is carried along with the armature during
the last portion of the motion, and the movement of this lever is utilized for increasing
the tension of the armature spring or for putting into tension an auxiliary spring by
which the action of the armature spring is reinforced when the armature is strongly
attracted.
Reference is to be had to the annexed sheet of drawings forming part of this
specification wherein-
Figure 1 is a side elevation of one form of the self adjusting relay, all the parts
being shown in the positions they occupy when the relay is at rest.
Figure 2 shows the same relay with the armature in the position it occupies when
acted upon by a feeble current.
Figure 3 is a side-elevation of the relay, the parts being in the position they assume
when acted upon by a strong current.
In this relay, the line wires are connected by the binding screws a a to the
terminals A A of the electro-magnet coils B. The cores b of this electro-magnet are
fixed to a base plate 6' and their poles are recessed to receive the correspondingly shaped
armature c. This armature is secured to the armature lever C, pivoted at d to the
standard D, which carries two adjustable stop screws d' d¹, for limiting at will the
play of the armature lever.
The arm of the lever C, to which the armature c is fixed, is made for the greater
part of its length, of a flexible leaf spring ct, having a platinum contact piece c¹
secured to its free end. While the relay is at rest, the contact piece c¹ bears against
the screw e screwed in a tapped hole in the standard E and provided with a point of
insulating material. When the armature c is attracted, the contact piece c' closes the
local circuit by bearing against the screw e¹ likewise screwed into the standard E. To
the other end of the armature lever C is attached, by means of an adjusting screw c³,
one end of an antagonistic spring c³, whose other end is connected to one end of a
small two-armed lever G, pivoted at f on a standard F. The other end of the lever G
bears upon one end of another two-armed lever H, pivoted at k to a pillar K, the end
of this lever H against which the lever G' bears, resting on a set-screw i movable in a
small tapped tube I. The other end of the lever H extends beneath the armature c,
so as to be depressed thereby when under the action of a strong current flowing through
the line, the leaf spring c is inflected and the armature caused to approach closely the
poles of the electro-magnet. This mode of operation of the relay is illustrated by
Figure 3, where the armature c, entering the recesses of the poles, forces downward
one end of the lever H, while the other end of this lever rises and carries along with
it the free end of the lever G, whereby tho spring c is put in tension.
As clearly shown in Figure 1, the electric communication of the terminals L L of
the local circuit is formed in the relay by the standard E, the contact-screw e¹, the
contact-piece c', the leaf spring ct, the lever C, the coiled spring c³, the lever G and
the upright F.
It will be understood, that, when the relay is to be worked by the interruption of a
constant current, the screw e¹ should be provided with a point of insulating material
and the screw e with a metallic point.
As already stated, it is not necessary, that the lever H, which is carried along with
the armature c when this latter is fully attracted, should increase the tension of the
antagonistic spring c* of the armature lever, but this spring may be invariably
adjusted for the action of feeble currents, and another additional spring may be pro-
vided and so arranged as to be put in tension by the lever H, while the armature is
performing the last portion of its motion towards the poles. Moreover, if an additional
spring be provided, the lever interposed between the armature and the spring may be
dispensed with, and the spring be so arranged as to be directly put in tension by the
armature. It is obvious that all springs may be replaced by suitable equivalents.

page_text: Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is-
1. In a telegraphic relay, the combination with a springy or flexible armature lever
which admits of the armature moving a short distance toward the poles of the electro-
magnet after the local circuit has been closed, of a spring, which is put in tension by
the armature whilst the latter is performing this last portion of its motion, and
whereby the armature is retracted when the line circuit is broken, substantially as
specified.
2. In a telegraphic relay, the combination with a springy, flexible armature lever,
which admits of the armature moving a short distance towards the poles of the electro-
magnet after the local circuit has been closed, of a lever so arranged as to be carried
along by the armature during the last portion of its motion towards the poles, and of
a spring so connected to this lever as to be put in tension by the motion of the lever
when it is acted on by the armature, as and for the purpose specified.
3. In a telegraphic relay, the combination with a springy, flexible armature lever,
which admits of the armature moving a short distance towards the poles of the electro-
magnet after the local circuit has been closed, of a two-armed lever so arranged that
one end of the same will be carried along by the armature during the last portion of
its motion towards the poles, and of another two-armed lever supported by the other
end of the first one and so connected to the antagonistic spring of the armature-lever,
that the tension of this spring will be increased by the motion transmitted to the second
lever from the first when the armature acts thereon, substantially as shown and
described.