Improvements in Telegraphic Relays.
Year: 1899

page_text: Date of Application, 9th Jan., 1893
Complete Specification Left, 9th Oct., 1899-Accepted, 25th Nov., 1899
Improvements in Telegraphic Relays.
1, ROBERT WILLIAM PAUL, of 44, Hatton Garden, E.C., in the County of London,
Electrician and Manufacturer of Scientific Instruments, do hereby declare the
nature of this invention to be as follows;-
My invention consists of improvements in telegraphic relays with the objects
of ensuring the make and break of contact between the tongue of the relay and the
fixed contact point or points when the force available for actuating the moving
parts is small, and of making such contact of sufficient duration to work the local
It is particularly
receiver, and of preventing sticking of the contact points.
advantageous in the case of the form of relay in which the moving part consists
of a coil suspended or pivotted in a magnetic field, but is applicable to other
forms in which an armature or magnet is moved on the passage of the line current.
In such instruments the play of the coil or other working part is limited by the
play of the tongue which is attached to it, so that when the line current is weak
the contact pressure is feeble, since a considerable part of the energy is absorbed
in starting the coil from its resting position, and overcoming the tendency of the
tongue to stick against its stop, so that it gains very slight momentum before its
motion is arrested by the contact point. Also when the controlling force on the
moving coil or other part is small. the tongue tends to stick against the contact
point, or striking it feebly it chatters against it forming successive contacts.
In applying my invention I arrange that the coil or other moving part shall be
free to move somewhat before throwing over the tongue. To enable this to be
effected I pivot or suspend the tongue on a separate axis, preferably parallel to
that of the coil, and the coil acts upon the tongue through a lever, fork or an
elastic connection; so that when the coil is actuated by the line current it at first
moves freely, gaining momentum before actuating the tongue, which it then
In order to avoid
throws over onto the contact point with considerable force.
rebounding or chattering of the contacts I prefer to allow the coil to move as
far as is allowable by the speed of working required, and to obsorb its energy,
after contact has been made, in the elastic connection of the tongue. Such elastic
connection I may make by forming the end of the tongue into a light flat spring,
which plays in a V formed on a lever attached to the moving coil. By regulating
the distance of the spring from the bottom of the V, the amount of free move-
ment of the coil, subject of course to any controlling force which is applied to it,
may be regulated, and after contact has been made by the pressure of one side of
the Vor fork against the spring, the return swing of the coil helps to prevent
sticking at the contacts. In order to further obviate sticking at the contacts I
may cause the tongue to be acted on by a force, such as gravity, a spring or
armature, to return it to its neutral or resting position, and one advantage of this
invention is that such force may be greater than when the same force acts on the
coil itself, on account of the greater energy of the coil due to the momentum
gained which overcomes such force on making contact.
Another advantage due to the elastic connection between the moving part and

page_text: Του
tongue is that the relay so constructed will work with largely different current
strengths if required, without alteration of the adjustments, for example with
TJ, milliampere and 1 milliampere. But in order to provide for varying require-
ments I prefer to provide suitable adjustments for the controlling force on the
coil, and for limiting its motion, for the damping of the motions of the coil more
or less by a metallic frame or winding which may be more or less short circuited,
for the duration of engagement or amount of play between the coil and tongue,
for the length and tension of the acting part of the spring or fork connecting
them, and the distance of the contact on the tongue from the axis around which
the tongue turns, and for the controlling force which may be used to return the
tongue to its resting position.
Dated this Ninth day of January 1899
Improvements in Telegraphic Relays.
I, ROBERT WILLIAM PAUL, of 44, Hatton Garden, E.C., in the County of London,
Electrician and Manufacturer of Scientific Instruments, 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:-
My invention consists of improvements in telegraphic relays with the object of
ensuring a certain contact when the force actuating the moving parts is small.
It is particularly advantageous in relays in which the actuating part consists
of a coil moving in a magnetic field, but is applicable to other forms.
In such relays as ordinarily constructed the play of the coil or other working
part is limited by the play of the tongue which is attached to it, and carries the
local current, hence the contact pressure is feeble when the line current is small,
and owing to the limited movement very small momentum is gained by the coil
before it is arrested by the contact points.
In applying my invention 1 pivot or suspend the contact tongue on an axis
separate from that of the coil and so connect the tongue to the coil that the latter
may move slightly so as to gain momentum before throwing over the tongue.
In order that the method of carrying out this invention may be more fully
understood reference is made to the accompanying drawings.
Fig. 1 shows a relay, constructed according to this invention, in elevation, and
Fig. 2 in plan.
1 is an insulating base-plate carrying terminals CZ D) U.
2 is an insulating disc attached to 1, on which a suitable cover, not shown in
the drawing, is fitted.
3 is a thin sub-base covering 1, which is hollow to contain the connections as
described below.
4 is an insulating plate so mounted upon 2 as to be readily removable, and
carrying a coek 5 on which the working parts are mounted,
6 is a ring magnet with suitably shaped poles, and provided with an armature
or core 7 carried on the cock 5 by the support 8.
9 is a coil which may be wound on an aluminium former, the current being led
throoh the controlling hair-spring 10 and the adjustable arm 11, by which the
tension is regulated, and led out by a flexible spiral or another spring not shown
in the drawing.
The ends of the coil are thus connected to the terminals D U for connection to
the line circuit.
Attached to the coil is the fork 12 which acts on the relay tongue.

page_text: The relay tongue is supported from the block 14 which is threaded on the
screw 13 to enable it to be easily adjusted vertically, and the manner of its
attachment is shown in elevation in Fig. 3.
The parts shown in Fig. 3 are attached to the block 14 by screws passing into
slots to render this part easily detachable for cleaning.
Referring to Fig. 3, 15 is an ivory or other insulating block to which are
screwed the plates 16 and 17 carrying the pivot screws on which the axis of the
tongue works.
Connection is made to this tongue through the adjusting arm 18 and the hair-
spring 21, and the local current entering at one of the terminals C or Z passes
through this spring to the tongue and thence to the contact screw 19, and SO
to the other local terminal.
When in position as shown in Fig. 2 the end of the tongue which may be a
light flat spring, plays in the fork 12 so as to be actuated by the coil and the
spring 21 may control the tongue so as to tend to throw it off the contact and
prevent sticking.
In order to centre or adjust the tongue in the fork the screw 22 is provided by
which the block 14 is adjustable round the screw 13, being pressed inward against
this screw by the spring 24 and in order to adjust the amount of play of the
tongue in the fork the fork may be taper and the height of the tongue adjustablo
by turning the screw 13.
To enable the local contact arm to be easily turned aside for cleaning, the
spring 24, is arranged to bear on either of two Hats on the back of the block 14,
to hold the latter over to one side when required.
To provide for easily removing the whole of the working parts without trouble-
some disconnecting there are arranged on the plate four metal plates 25 to which
the working parts are severally connected and key-hole slots are cut in the plate 4
so that the holding down screws which pass through it into plates on the under
surface of 2 may be loosened and allow the plate 4 with the whole of the working
parts attached to be pushed back and lifted out.
It is found that the spring 21 may be fairly powerful compared with the
spring 10 controlling the coil since the coil can be allowed to gain a certain
momentum before moving the tongue.
In order to provide a simple adjustment for altering the sensitiveness of the
relay there are attached to a plate 20 (Fig. 1) two stop screws to limit the play
of the coil so that its controlling spring may be put in tension without altering
the normal position of the coil, but I find that, provided that the tongue 20 is
made sufficiently yielding, widely different currents may be sent through the coil
without causing chattering or rebounding of the contacts, and the amount of yield-
ing of the tongue 20 may be conveniently adjusted by sliding out the slotted
block 15.
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. In relays for telegraphic and similar purposes pivotting or suspending the
tongue or contact arm on a separate axis to that of the actuating part.
2. The adjustments for regulating the position of a separately pivotted tongue
substantially as described.
3. In a moving-coil relay the construction for rendering the working parts
easily detachable substantially as described.
4. The relay mechanism substantially as described.
Dated this 9th day of October 1899