Year: 1888

page_text: Date of Application, 14th Feb., 1888
Complete Specification Left, 14th Nov., 1888
Complete Specification Accepted, 21st Dec., 1888
I, ALFRED GRAHAM, of 109 Farringdon Road, in the City of London, Electrician,
do hereby declare the nature of this Invention to be as follows :-
The object of my Invention is to provide a simple and efficient switch by means of
which contacts can be made for communicating with different places, which switch on
being released automatically returns to its normal position in which the circuit with
its Bell, Annunciator Telephone, or Instrument, is completed.
According to my Invention I mount in a suitable case or a suitable board a series
of contact pieces to which lead wires from the several places with which communica-
tion is to be had. Capable of being moved along in front of or behind these contact
pieces is a contact maker by which the circuit with the telephone or other Instrument
can be completed from any one of the places according to which of the contacts on the
board or in the box is in contact with the moveable contact piece. There may, if
desired, be moveable contact pieces for each of the contacts on the board or in the box.
The moveable contact or contacts is or are provided with means for indicating which
contacts have been made by the operator. The moveable contact or contacts is or are
retained in the position to which they have been brought by means of a catch or pawl
or catches or pawls which is or are acted upon by a device operated by a push button
or the like so that the pawl or catch which engages the said contact is released when
the said contact returns to its normal position. According to one arrangement of my
Invention I arrange the fixed contacts in the arc of a circle and I mount the moveable
contact on a centre and provide it with a handle which projects outside the box in
which the contacts are situated and is there provided with a pointer moving over a
dial or indicator marked with numbers or signs shewing which contacts are made.
On the boss of the moveable contact or on other suitable part is a ratchet wheel or
part of a wheel provided with ratchet teeth with which engages under the action of a
spring, a pawl which is acted upon by a piece actuated by a push button or the like
so as to release the pawl from engagement with the ratchet wheel and allow the
moveable contact to return to its normal position under the action of a spring or
weight. Or the fixed contacts may be arranged in a straight line and the moveable

page_text: contact be caused to slide along in a straight guide parallel thereto. Or there may be
a moveable contact for each fixed contact so that by depressing either moveable contact
it can be caused to engage with the corresponding fixed contact which may be in the
form of a retaining hook capable of being released by a piece operated by a push
button or the like, which piece can be caused to act on all the catch-pieces and so
cause whichever moveable contact may be engaged with its fixed contact to be released
so that the instrument returns to its normal condition.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C.,
Agents for the said Alfred Graham.
I ALFRED GRAHAM of 109 Farringdon Road in the City of London Electrician 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:
The object of my Invention is to provide a simple and efficient switch by means of
which contacts can be made for communicating with different places which switch on
being released automatically returns to its normal position in which the circuit with
its bell, annunciator, telephone, or other instrument is completed.
According to my invention I mount in a suitable case or on a suitable board a series
of contact pieces to which wires are led from the several places with which communica-
tion is to be had. Capable of being moved along in front of or behind these contact
pieces is a contact maker by which the circuit with the telephone or other instrument
can be completed from any one of the places according to which of the contacts on the
board or in the box is in contact with the moveable contact piece. There may if
desired be moveable contact pieces for each of the contacts on the board or in the
box. The moveable contact or contacts is or are provided with means for indicating
which contacts have been made by the operator. The moveable contact or contacts
is or are retained in the position to which they have been brought by means of a catch
or pawl or catches or pawls which is or are acted upon by a device operated by a push
button or the like so that the pawl or catch which engages the said contact is released
when the said contact returns to its normal position. I will describe with reference to
the accompanying drawings an arrangement of my Invention.

page_text: Figure 1 is a front view. Figure 2 a back view and Figure 3 a side view. Figure
4 is a diagram shewing a combination of four switches.
I arrange the fixed contacts formed by the springs a in the are of a circle on the
board A and I mount the moveable contact B on a centre band provide it with a
handle C which projects on the outer side of the board A and is provided with a
pointer D moving over a dial or indicator marked with numbers or signs shewing
which contacts are made. These are shown at e as being small discs inserted into the
board A and marked with numbers each switch containing one contact marked O and
having omitted the number corresponding to the number of switch in the series for
example as shewn in Figure 4-No. 1 switch contains contacts marked 0, 2, 3, 4—
No. 2 switch is marked 0, 1, 3, 4-No. 3 switch is marked 0, 1, 2, 4-No. 4 switch is
marked 0, 1, 2, 3 and so on according to the number of switches employed.
On the boss of the moveable contact is a ratchet wheel 3 or part of a wheel
provided with ratchet teeth with which engages a pawl f carried by a spring g which
causes the pawlf to engage between such of the teeth of the wheel b³ as may be
opposite it. The pawl is released by the spring g being acted upon by a push button /
or the like so as to press back the spring and release the pawl from engagement
with the ratchet wheel and allow the moveable contact to return to its normal position
under the action of a spring I or weight. Or the fixed contacts a may be arranged in
a straight line and the moveable contact be caused to slide along in a straight guide
parallel thereto. Or there may be a moveable contact for each fixed contact so that by
depressing either moveable contact it can be caused to engage with the corresponding
fixed contact which may be in the form of a retaining hook capable of being released
by a piece operated by a push button or the like which piece can be caused to act on
all the catch pieces and so cause whichever moveable contact may be engaged with
its fixed contact to be released so that the instrument returns to its normal condition.
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 :-
A switch for electric circuits arranged and operating substantially as hereinbefore
described.