Improvements in Electric Switches.
Year: 1898

page_text: Date of Application, 2nd Apr., 1898-Accepted, 1st Apr., 1899
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
1, JEAN MARIE DOMINIQUE SOULÉ, of Bagnères de Bigorre, Department of
Hautes Pyrénées, France, Manufacturer, 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 consists of improvements in the construction of electric
switches, and especially those used for electric lighting.
The annexed drawings shew a switch constructed according to my invention.
Fig. 1 shews a sectional elevation of the switch on the line C D, Fig. 2.
Fig. 2 shews a plan view of the same, the key C and the contact plate B being
removed, with the exception of one snug E, on plate B¹, hereinafter described.
Fig. 3 shews a plan view of the key of the switch as seen from below.
Fig. 4 shews an elevation and a plan view of the contact plate. The improved
switch consists of a porcelain base A (Figs. 1 and 2) such as are generally used
in switches, but provided with a projecting central core and constructed with-
out a thread for screwing on the cover. The porcelain key C (Figs. 1 and 3)
used for operating the contact plate, as hereinafter described, is made in one
piece without the addition of metal pieces of any kind screwed or joined thereto,
and the special form of this key, hereinafter described, allows the cover to be
secured in place by means of a nut J screwed on to the upper end of the bolt T
in the key, so that, when the switch is fixed in place, the inner metal pieces will
be out of the reach of inexperienced hands.
The porcelain cover m is held in place by the flange U of the key (Fig. 1);
and in the key which has a central bore is fixed a spring S which reduces the
effect of any slight difference, which may have been produced in the manu-
facture, obtaining thereby an easy but effective pressure on the cover m.
small ring of some soft fabric may be placed between the key and the cover under
the flange U to prevent the rubbing together of two porcelain parts.
A
The switches may in certain cases be made with a porcelain base A and a
cover of metal or wholly or partly of insulating material such as compressed
wood, ebonite or papier mache.
Under the base A is a cavity in which is located the angular head T¹ of a bolt T
to prevent the latter from turning whilst the nuts are being screwed thereon.
On this bolt is slipped a small ring of copper or other suitable material placed
on the central core A¹ of the base, and on this ring is placed a contact plate B¹
for closing the circuit. A nut F is screwed on the bolt T and guides the cou-
tact plate B by a shoulder arranged on said bolt which passes through said
contact plate.
The key is adjusted by screwing the nut J at the upper end of the bolt T.
The contact plate B₁ establishing circuit is flat, and when it is desired to make
the circuit it is caused to slide between two small lower plates P and P
placed on the base, and two small curved upper plates P P¹, each set (P", P
and P, P¹) of which forms one of the poles of the switch. This arrangement

page_text: ensures a large bearing surface above and below the contact plate thus avoiding
the heating due to defective or too small contacts.
The connection of the two conducting wires with the poles are established
by hexagonal nuts K K (Fig. 2) which form the terminals. The current passes
into the contact plate without any intermediate connection and thus from one
pole to the other. The contact plate is made with two snugs which project in
opposite directions, one E on one face of the contact plate and the other E¹ on
the other face Figs. 1 and 4. In mounting the apparatus, one of the snugs E
descends into an annular cavity formed around the central core of the base A; to
this snug is fixed one of the ends of a spiral spring R placed in the annular
cavity, the other end of this spring being fixed in a groove B Fig. 2 made in the
central core of the base, and by this arrangement the spring is insulated. This
spring is arranged to withdraw the contact plate quickly when the circuit is
being broken. A boss or projection 1 formed in the base A serves as a stop to
the action of spring, and this projection obviates the necessity of using metallic
stops.
The second snug E¹ of the contact plate is located in a curved notch V (Figs. 1
and 3) of the key; the contact plate supports the key, and when it is desired to
make the circuit, the contact plate is operated by the movement of the key, by one
end of the notch V being brought against the snug E¹. The other end of the notch
will operate in the same way to break the circuit. The moment when the contact
plate leaves the two sets of plates (P", P and P, P) the spring R brings it
sharply back independently of the key, to a position of rest, where it remains
until the key is next operated.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
(1) An electrical switch characterised by a non-screw-down cover, the use of
a straight contact plate with snugs thereon, and by a base adapted to receive
a controlling spring for the contact plate, this spring being insulated, substan-
tially as, and for the purpose set forth.
(2) In an electrical switch as claimed in Claim 1, a special arrangement of
the key thereby obviating the use of a screw-down cover, said cover being held
to the base of the switch by a flange U on the key C, this key being centrally
bored to receive a bolt, the various parts of which serve at the same time to
keep the contact plate in position and to keep the cover on the base with a
suitable pressure, substantially as and for the purpose set forth.
(3) In an electrical switch as claimed in Claim 1, a straight contact plate,
bearing two snugs EE passing respectively one into a ring of a controlling
spring and the other into a notch in the key, substantially as and for the pur-
pose set forth.
(4) In an electrical switch as claimed in Claim 1, a base A provided with a
recess to receive the controlling spring operating the contact plate B', the core
of this base having a notch B for retaining one end of the spring and a boss 1)
for serving as a stop for the other end of the said spring, which thus becomes
insulated from the contact plate and protected from the influence of the current,
substantially as and for the purpose set forth.
Dated this 21at
1000
S. S. BROMHEAD,
Agent for Applicant, 171, Queen Victoria Street, London, E.C.