Improvements in or connected with Automatic Switches for Controlling Electric Lamps.
Year: 1896

page_text: Date of Application, 13th Oct., 1896
Improvements in or connected with Automatic Switches for
Controlling Electric Lamps.
I, WILLIAM JAMES DAVY, Engineer, of 27 Drayton Park, Highbury, in the
County of London, do hereby declare the nature of this invention to be as
follows:-
This invention for improvements in or connected with automatic switches for
controlling electric lamps relates more particularly to switches for use in systems
in which arc lamps supplied by one circuit are employed for lighting during one
period or one part of a night and incandescent lamps supplied by a separate or
household circuit are employed at another period or other part of the night,
and has for its object to control the switches for the incandescent lamps by means
of the arc lamp circuit in such manner that the incandescent lamp switches are
turned off when the arc lamps are alight and can be left off or on as desired when
the current to the arc circuit is stopped.
An automatic switch constructed according to this invention consists essentially
of an electromagnet placed in the controlling av lamp circuit and having a
reciprocatory armature operatively connected to a rotatable disc by a pawl and
ratchet or other suitable gear so that each reciprocation advances the disc one step
forward. The said disc carries, or is formed with, a contact ring divided alter-
nately into segments of insulating and of metallic conducting material on which
rest two switch contact plates one of which is connected to and oscillates with the
armature while the other is fixed in position relatively to it, the incandescent
lamp circuit being completed through the said contact plates and disc. The motion
of the armature is limited by suitable stops and is returned to its normal or open
position by a spring or other suitable means.
The action is as follows:-Assuming that the arc lamps have been switched
on to light the streets and the circuit being consequently closed, the electromagnet
is energised and attracts its armature causing the contact ring to advance a step
and thereby place a metallic segment in contact with the fixed switch contact
plate while the movable switch contact plate remains insulated. On switching
off the are lamps by breaking their circuit the magnet is de-energised and allows
the movable switch. contact plate to return to its normal position by the aid of
the spring, the incandescent lamp circuit being thereby closed.
In order to extinguish the incandescent lamps the arc lamp circuit is again
completed and broken causing the contact ring to advance a step and the switch
contact plate to rest upon the insulating segments, thereby breaking the incan-
descent lamp circuit.
Dated this 13th day of October 1806
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.

page_text: Improvements in or connected with Automatic Switches for
Controlling Electric Lamps.
I, WILLIAM JAMES DAVY, Engineer, of 27 Drayton Park, Highbury, in the
County of London, 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:—
This invention for improvements in or connected with automatic switches for
controlling electric lamps relates more particularly to switches for use in systems
in which arc lamps supplied by one circuit are employed for lighting during one
period or one part of a night and incandescent lamps supplied by a separate or
household circuit are employed at another period or other part of the night, and
has for its object to control the switches for the incandescent lamps by means of
the arc lamp circuit in such manner that the incandescent lamp switches are
turned off when the arc lamps are alight and can be left off or on as desired when
the current to the arc circuit is stopped.
In the accompanying sheet of illustrative drawings:
Fig 1 is a plan, Fig. 2 an elevation and Fig. 3 a sectional elevation of a switch
constructed according to this invention.
An electro-magnet a is mounted in a fixing plate b secured to an insulating
slab c connected to a base d by pillars e of insulating material. Mounted on a
supporting pin f secured in the fixing plate b is a reciprocatory armature g having
an arm to which is connected a pawl i engaging with a ratchet toothed ring
secured to a rotatable disc m of insulating material, the whole being mounted
on the supporting pin f so that at each reciprocation of the armature g the disc m
is rotated through an angle corresponding to one tooth of the ratchet ring, the
said ring being prevented from running back on the backward motion of the
pawl i, by means of a detent pin n pressed into engagement with the ratchet teeth
by means of a suitable spring. To the disc m is secured a contact ring o divided
alternately into metallic and insulating segments 29 each corresponding to one
tooth of the ratchet ring 7. The arm h carries an insulated spring r to the end
of which is secured a contact plate s making contact with the ring o while a similar
insulated spring rl and contact plate s' is secured to the slab c. The contacts are
curved as shown to bridge one division of the contact' ring, thus forming a double
contact, and is pressed against the ring o by the flexible springs thereby insuring
a perfect contact. The armature g is returned to its open or normal position.
after displacement by means of the spring t.
The action is as follows: --Assuming that the arc lamps have been switched on
to light the streets, and that the arc lamp circuit is consequently closed, the electro-
magnet a, which is in the arc lamp circuit, is energised and attracts its armature
causing the contact ring o to advance a step and thereby place metallic segments p
in contact with the fixed switch contact plate s' while the movable switch contact
plates remains insulated. On switching off the arc lamps, by breaking their
circuit. the magnet a is de-energised and allows the movable switch contact plate
to return to its normal position by the aid of the spring t, the incandescent lamp
circuit being thereby closed through terminal v, spring r, contact s, ring o,
contact s¹, spring r¹, fuse connection wo and terminal ..
In order to extinguish the incandescent lamps the arc lamp circuit is again
completed and broken causing the contact ring to advance a step and the switch
contact plates s s¹ to rest upon the insulating segments 'g, thereby breaking the
incandescent lamp circuit as will be readily understood.

page_text: 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. An automatic switch for controlling electric incandescent lamps by means
of an arc lamp circuit comprising an electromagnet placed in the controlling arc
lamp circuit, à reciprocating armature operatively connected to an insulated and
rotatable contact ring, and insulated contact plates, making contact with the said
contact ring, one being connected to the said armature while the other is fixed
relatively to it, the whole substantially as described for the purpose set forth.
2. In an automatic switch for controlling electric incandescent lamps by
means of an arc lamp circuit, the combination with an electromagnet and recipro-
catory armature of two insulated double contact plates, one fixed while the other
is connected to and moves with the armature, an insulated contact ring divided into
alternate insulating and conducting segments, and a ratchet ring and pawl
operated by the reciprocation of the armature so as to advance the contact ring
one division for each reciprocation substantially as described.
3. The improvements in or connected with automatic switches for controlling
electric lamps the whole arranged, constructed and operating substantially as
described and shown.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.