Improvements in Electric Switches.
Year: 1892

page_text: Date of Application, 19th May, 1892
Complete Specification Left, 14th Feb., 1893-Accepted, 15th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electric Switches.
We, JOHN MACINTOSH, MACKAY MUNRO, of The Munro's Electrical
Manufacturing Company Limited, 9 Holland Place, Glasgow, in the County of
Lanark, North Britain and JAMES MCFARLANE, Manager of said Company
do hereby declare the nature of this invention to be as follows:-
The object of this invention is to provide an electric switch or interrupter of
design at once more compact, more reliable, and more rapid in break, than
hitherto.
66
"
or
In this improved switch a moveable bar or contact lever "makes"
"breaks" a circuit by passing between or being withdrawn from two spring
clips of metal, preferably of hard copper. This contact lever is pushed into the
on" position by means of an insulated handle attached thereto. A. spring pulls
or presses against the lever and this spring is amply strong enough to force it ont
of the " on "into the "off" position. When however the contact lever is fully
home into the " on position a detent falls into a notch in the pivot disc of the
lever so locking it into "on"-position. The spring which otherwise tends to throw
the lever out now keeps all fast and safe against accidental release. To throw the
switch "off" the detent is withdrawn by pushing a suitably arranged button or
supplementary lever. Whenever the detent is withdrawn the contact lever is
pulled sharply off by the aforesaid spring, the switch is so constructed (and this is
the chief individual point of novelty in the switch) that the appliance which
presses out the detent also tends to press out the contact lever, with this object
that if the spring ever fails, the switch is still a good serviceable "hand
"gravity" switch.
and
"
6
or
or
When desired "contact brushes "bearing springs" are provided to make.
more perfect contact between the contact lever and its pivot bracket which is the
terminal of the switch unless where the current is merely passed transversely
across contact bar from one contact clip to the other, in which case the two base
extensions of these clips form the switch terminals.
As an alternative method in place of the little detent with knob attached we
might use a small lever which would serve the purpose of putting the switch into
the "off" and "on" position, the other parts remaining the same.
Dated this 18th day of May 1892.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicants' Agents.
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
We, JOHN MACINTOSH MACKAY MUNRO, of The Munro's Electrical
Manufacturing Company Limited, 9 Holland Place, Glasgow, in the County of
Lanark, North Britain, and JAMES MCFARLANE, Manager of said Company,
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 :-
Our invention has for its object to provide an electric switch or interruptor
more compact, more reliable, and more rapid in break than hitherto.

page_text: In order that our invention may be properly understood and readily carried into
effect we have hereunto appended an explanatory sheet of drawings in the several
figures of which corresponding parts are marked with the same letters of
reference.
Figure 1 is an elevation showing the switch in the "on" position.
Figure 2 is a similar view showing it on the "off" position.
Figure 3 is a plan of Figure 2.
"
on
"
In our improved switch a movable bar or contact lever A makes or breaks the
circuit by passing between or being withdrawn from two spring clips B, B' of any
suitable metal. This contact lever A is pushed into the "on position by means
of an insulated handle C attached thereto by means of a screw or otherwise. A
spring D pulls or presses against the lever A, and this spring is of sufficient
strength to force the lever A out of the " on "into the "off" position. When
however the contact lever A is fully home into the " on position a detent E falls
into a notch F in the pivot disc a' of the lever A, thus locking it into "
position. To throw the switch "off," the detent E is withdrawn by pressing a
suitably arranged button G or supplementary lever, and whenever the detent E is
withdrawn the contact lever A is pulled sharply off by means of the spring D.
The switch is so constructed that in the event of the spring D not acting, the arm e
of the detent E pressing against the contact lever A on the release of the detent
tends to throw out the contact lever so that the switch is still a good serviceable
hand or gravity one.
Contact brushes
and
or
bearing springs I are provided to make more perfect
contact between the contact lever and its pivot bracket which is the terminal of
the switch unless where the current is merely passed transversely across contact
bar from one contact clip to the other, in which case the two base extensions of
these clips form a switch terminal.
As an alternative method, in place of the little detent with knob attached we
might use a small lever which would serve the purpose of putting the switch into
the "off" and "on" position, the other parts remaining the same.
.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
"
1. The general arrangement and combination of the parts for putting the
switch into "on position, substantially as described and shown on the accom-
panying sheet of drawings.
2. The general arrangement and combination of the parts for putting the switch
into "off" position, substantially as described and shown on the accompanying
sheet of drawings.
Dated this 10th of Wohmuan 1002
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicants' Agents.