An Improved Electric Switch.
Year: 1890

page_text: Date of Application, 5th May, 1890
Complete Specification Left, 5th Feb., 1891-Accepted, 7th Mar., 1891
PROVISIONAL SPECIFICATION.
An Improved Electric Switch.
1, JOSEPH APPLETON, of the firm of Appleton, Burbey & Williamson,
Electrical Engineers, of 91, Queen Victoria Street, in the City of London, do
hereby declare the nature of the said invention to be as follows:-
In certain electric switches, at present largely in use, the circuit is closed by two
flat metallic spring tongue pieces mounted on an oscillating arm composed of non-
conducting material and held normally in the "current off" position by a spring,
so that the aforesaid tongue pieces are kept out of contact with the terminals, but
when it is required to close the circuit through the terminals, the spring tongue
pieces are pressed in between the contact surfaces of the said terminals by means of
an arm or handle turning on a fulcrum and provided with a tappet adapted to act
on the aforesaid oscillating arm in opposition to the spring acting upon the same.
Switches constructed in this manner have certain defects, one of which is that unless
the tongue pieces and the contact surfaces of the terminals are fitted accurately to
one another, the surfaces in contact are liable to be comparatively small and there-
fore of small conductive capacity; another of these defects is that in the event of
the spring acting upon the arm carrying the tongue pieces becoming weakened or
broken the said tongue pieces are not removed with certainty from contact with
the terminals when the switch handle is turned into the current off" position.
E:
The object of my present invention is to obriate more especially these two
defects, with the view of producing a more reliable switch than those lieretofore in
use, and for this purpose I employ arrangements of the following character:-
I provide a bracket or support for the switch handle somewhat similar to that
already in use and provided like it with a screwed cylindrical part for the attach-
ment of the usual bell or dome-shaped cover. 1 also mount the switch handle on a
fulcrum pin in the aforesaid bracket or support, much in the usual way, but instead
of forming the switch handle as a tappet at one end, I prolong it beyond the
fulcrum in a cylindrical or other suitable form, and mount thereon a ring-shaped
piece forming the switch contact maker, insulated from the handle by means of
suitable insulating material. The contact pieces, through which the circuit is to be
completed, are secured side by side on the china or other non-conducting base of the
switch and are each provided with a spring tongue so shaped and placed with
reference to the switch handle that, when the latter is turned into the current on
position, the aforesaid ring contact-maker, mounted on the prolongation thereof,
passes in between the said spring tongues and closes the circuit through them.
These spring tongues are preferably curved to correspond to the shape of the ring
contact-maker which passes in between them so that the surface of the tongues in
contact therewith shall be considerable, and to enable the ring contact-maker to
adapt itself to the curved part of the spring tongues for the said purpose of securing
considerable surface of contact, the ring may be mounted somewhat loosely on the
handle. Another object in curving the spring tongue contacts, is to enable them to
grasp and hold the ring contact-maker firmly in the current on position when
the same is passer in between the said tongues. A spring is provided to hold the
switch handle in the "current off" position; but in the event of this spring
becoming weakened or broken so that it fails to force the ring contact-maker away
clear of the contact tongues when the switch handle is turned into the "current off"
position, the spring-like ends of the tongues act on the back part of the cylindrical
surface of the ring contact maker and themselves jerk it away out of contact with
them. By these means therefore I am enabled to obviate on the one hand the
imperfect breaking of the circuit when the spring becomes weak or is broken, and

page_text: on the other hand large surfaces of contact between the terminals and the switch
contact maker are secured without such accurate fitting as is required in switches of
the ordinary construction.
J. APPLETON.
Per W. II. Beck,
115. Cannon Street, London, E.C., Agent.
COMPLETE SPECIFICATION,
An Improved Electric Switch.
I, JOSEPH APPLETON, of the firm of Appleton. Burbey and Williamson,
Electrical Engineers, of 91. Queen Victoria Street, in the City of London, do
hereby declare the nature of the said invention and in what manner the same is
to be performed, to be particularly described and ascertained in nul by the
following statement, reference being had to the accompanying sheet of drawings,
and to the letters and figures marked thereon, that is to say :-
In certain electric switches, at present largely in use, the circuit is closed by two
flat metallic spring-tongue pieces mounted on an oscillating arm composed of non-
ronducting material and held normally in the "current of position by a spring,
so that the aforesaid tongue pieces are kept out of contact with the terminals, but
when it is required to close the circuit through the terminals the spring-tongue
pieces are pressed in between the contact surfaces of the said terminals by means of
an arm or handle turning on a fulernum and provided with a tappet adapted to act
on the aforesaid oscillating arm in opposition to the spring acting upon the same.
Switches constructed in this manner have certain defirts one of which is that unless
the tongue pieces and the contact surfaces of the terminals are fitted accurately to
one another, the surfaces in ntact are liable to be comparatively small and
therefore of small conductive capacity: another of these defects, is that in the event
of the spring acting upon the arm carrying the tongue pieces becoming weakened
or broken, the said tongue pieces are not removed with certainty from contact
with the terminals when the switch handle is turned into the current off”
position.
The object of my present invention is to obviate more especially these two
defects, with the view of producing a more reliable switch than those heretofore in
use, and for this purpose I employ the arrangements, shown in the accompanying
sheet of drawings in which
Figure 1 is a side view of the mechanism of one of my improved switches.
Figure 2a front view and
Figure 3 a view taken at right angles to Figure 1.
A is a bracket or support for the switch handle somewhat similar to that already
in use and provided like it with a screwed cylindrical part B for the attachment of
the usual bell or dome-shaped cover shown only in dotted lines in the several
figures of the drawing. The switch handle D is mounted on a fulerum pin E in
the aforesaid bracket or support much in the usual way; but instead of forming
the switch handle 1 as a tappet at one end I prolong it beyond the fulerun in a
cylindrical or other suitably formed part D', and mount on such part a ring-shaped
piece forming the switch contact maker, insulated from the landle by means of
suitable insulating material interposed between the said ring and the
prolongation of the handle D. The contact pieces GH through which the
circuit is to be completed, are secured side by side on the china or other non-
conducting base I of the switch, and are each provided with a spring-tongue GH
so shaped and placed with reference to the switch handle that when the latter is
turned into the current on" position the aforesaid ring contact maker mounted
on the prolongation D' thereof passes in between the said spring tongues (and
closes the circuit through them. These spring tongues are preferably curved to
66

page_text: correspond to the shape of the ring contact maker F which passes in between them
so that the surface of the tongues in contact therewith shall be considerable, and to
enable the ring contact maker to adapt itself to the curved part of the spring
tongues for the said purpose of securing considerable surface of contact, the ring
may be mounted somewhat loosely on the part D' of the handle. Another object
in curving the spring tongue contacts (H. is to enable them to grasp and hold
the ring contact maker firmly in the "current on" position when the same is
passed in between the said tongues. A spring is provided to hold the switch
haudle in the current off" position seen in dotted lines in Figure 1; but in the
event of this spring J becoming weakened or broken so that it fails to force the
ring contact maker away clear of the contact tongues when the switch handle is
turned into the "current off" position, the spring-like ends of the tongues G¹ H'
act on the back part of the cylindrical surface of the ring contact maker F and
themselves jerk it away out of contact with them. By these means therefore I am
enabled to obviate on the one hand, the imperfect breaking of the circuit when the
spring becomes weak or is broken, and on the other hand large surfaces of contact
between the terminals and the switch contact maker are secured without such
accurate fitting as is required in switches of the ordinary construction.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
The improved electric switch, consisting of the pivoted handle D D', the ring
shaped contact maker F mounted on the said handle but insulated therefrom, and
the spring contact pieces G'H' shaped and curved to receive the said ring contact
maker F between them when the said handle and contact maker are in the current
on" position and to jerk the said handle and ring contact maker away clear of
themselves when the same are moved into the "current off" position, substantially
as hereinbefore described and illustrated in the drawings.
Dated this 5th dox of February 1891
Dated this 5th day of
February 11891
J. APPLETON.
Per W. H. Beck,
115, Cannon Street, London, E.C., Agent.