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 26th April 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 discon-
nection 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 which the two lines are normally

page_text: 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 from the ratchet leaving the pulley free to rotate and the
carrier to advance. As the pulley 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 is released from engagement with the sweep and is left stationary.
When 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 horizontal
carrier again stops in its path and engages with it. When the switch 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.