IMPROVEMENTS IN SWITCH APPARATUS FOR CONNECTING AND DISCONNECTING ELECTRICAL LINES FOR TELEGRAPHIC OR TELEPHONIC COMMUNI- CATION
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by John Imray at the Office of the
Commissioners of Patents on the 25th October 1883. Communicated to him
from abroad by Thomas Anthony Connolly of the District of Columbia in the
United States of America
JOHN IMRAY of N° 28 Southampton Buildings, Chancery Lane in the County
of Middlesex "IMPROVEMENTS IN SWITCH APPARATUS FOR CONNECTING AND
DISCONNECTING ELECTRICAL LINES FOR TELEGRAPHIC OR TELEPHONIC COMMUNI-
CATION" [communicated to him from abroad by Thomas Anthony Connolly of the
District of Columbia in the United States of America]
This invention relates to switch apparatus for effecting connection and dis-
connection of electric lines or conductors employed for telegraphic or telephonic
communication, so that in cases where a number of such lines radiate from a
central station or exchange, any one of these radiating lines can readily be put in
connection with any other.
In this apparatus, the motive power for effecting the connection is obtained by
mechanical means brought into operation and controlled by electrical appliances, so
as to avoid using the electric current to do mechanical work. The frame of the
apparatus has a series of horizontal bars, which form tracks for carriers that are
caused to slide to and fro along the bars by mechanical appliances, controlled by
electric devices, so that the carriers can be started and will move until, by the
action of the electric devices, they are stopped. There is one such carrier to each
of the electric lines. The frame has also a series of vertical bars which cross the
horizontal bars, so that a carrier in traversing the horizontal bars crosses
successively all the vertical bars, each of which is connected with one of the
electric lines. Hence, when the carrier of one line is moved along its track and
stopped at and in contact with the vertical bar of another line, electric connection
of these two lines is effected. As means of effecting engagement between the
carriers and the vertical bars, travellers are arranged to move up and down on the
vertical bars. When the carrier on any horizontal line stops in the path or in
front of one of the vertical bars, the moving traveller on the latter becomes
engaged with the then stationary carrier. By this engagement, the earth with
Pin 9.77

page_text: which the two lines are normally connected, is cut out of circuit and the two
lines become connected together. For moving the horizontal carriers, opposite
rotating screws, or worm shafts are arranged to give to and fro motion to a
sweep which traverses all the horizontal bars. At the extreme of its outstroke,
this sweep engages with any carrier that may be there and brings it back by its
instroke to what may be termed its home position, where it rests not forming
connection with any other line than its own. For moving each carrier forward
from its home position, a weight or spring is employed straining a belt which
passes over a pulley with sufficient friction to prevent slipping. On the pulley
shaft is a ratchet or toothed wheel which is engaged by a pawl or pin on the
armature of an electro-magnet in circuit with the line to which the carrier belongs.
When this line is put in circuit with a battery, the pawl is disengaged froin the
As the pulley
ratchet leaving the pulley free to rotate and the carrier to advance.
rotates, it works a make and break device in the line circuit, causing movement of
an index on a dial or of an equivalent registering device at the distant terminal of
the line, as for example at the box of a subscriber in a telephone exchange. By
means of a switch lever or key at the dial, the electric circuit can be broken when
the carrier reaches some particular vertical bar, so that the carrier stops there, the
index stopping also. The vertical travellers are caused to move up and down by
a sweep worked by opposite screws like those which move the sweep for the
horizontal carriers. A vertical traveller, when it engages with a horizontal carrier,
When
is released from engagement with the sweep and is left stationary.
the horizontal carrier is moved away from engagement with a traveller, the
vertical sweep again engages the traveller moving it up and down until a
When the switch
horizontal carrier again stops in its path and engages with it.
lever or key at the registering instrument opens the circuit, the pawl on the
armature of the electro-magnet at the switch board engages the ratchet and
prevents the pulley from rotating, thus stopping the horizontal carrier. When the
circuit is again closed, the pulley is released and the carrier moves to that end of
the switch frame where the sweep engaging with it brings it back to its home
position.