Improvements
Year: 1897

page_text: Date of Application, 2nd Nov., 1897
Complete Specification Left, 2nd Aug., 1898-Accepted, 3rd Sept., 1898
πριονι
VITTORIO GIOVANNI LIRONI, 251, Western Bank, Sheffield, Electrical Engineer,
I do hereby declare the nature of this invention to be as follows:-
My invention has for its object the production of an improved form of electric
switch, ensuring perfect insulation & mechanical construction, and is carried out
in the following manner:-A suitable base of insulating material preferably.
china, earthenware or porcelain is provided of special shape & construction having
pillars or projections arranged so as to carry the switch parts, at the same time
A contact arm of rectangular
forming an insulating medium between them.
or other special shape so arranged as to embrace a block of insulating material,
which contact arm is pivoted at one end to one or two of the pillars of the before
mentioned base. Two contact pieces & suitable terminals are provided so that
the contact arm moving on its pivot is capable of making electrical contact
therewith. These contact pieces are of special shape so that the contact arm
makes electrical connection on four distinct surfaces. Upon the top of the
before mentioned three pillars is mounted a ring which serves to carry the switch
handle, which switch handle is formed after & is similar to that known as the
in contact
"tumbler knob." In actuating the switch handle a roller comes
& depresses the before mentioned block of china, which is embraced by the switch
A suitable
contact arm, thereby causing the arm to make electrical contact.
spring is provided in the base to assist in throwing off the contact arm when
breaking circuit. The piece of metal known as the heel piece in a tumbler
switch is formed & is part of the before mentioned piece of china or other insu-
lating material. By these means it is possible to construct a switch the whole
insulation of which can be effected by the use of porcelain, china or earthen-
ware.
Dated this First day of November 1897.
Improvements in Pi
I, VITTORIO GIOVANNI LIRONI, of 251, Western Bank, Sheffield, Electrical
Engineer, do hereby declare the nature of this invention and in what manner
the same has to be performed, to be particularly described and ascertained in and
by the following statement: —
My invention of improvements in electric switches relates to the construc-
tion of such articles whereby perfect insulation is assured with certainty of

page_text: The annexed sheet of drawings illustrates my invention, and similar letters
of reference indicate similar parts in any of the figures.
Fig. 1, represents a plan, and Fig. 2, an elevation of the base, made of insu-
lating material.
Fig. 3, plan of the base as Fig. 1-with the terminals and contact arm in
position.
shows the relative position of the switch handle with the contact arm
Fig.
and spring.
In carrying out my invention as shown in the drawings I make a suitable
base or block A of any suitable material, such as porcelain, having pillars or
raised parts B1, B³, & B³ upon which a ring or support for the handle or knob K
is fixed; it is also recessed at C, to receive the switching appliances, and forms
the insulating medium between the various parts.
A cover of porcelain or the like (not shown) is used to enclose all the parts,
and it may be screwed upon threads formed upon the pillars B, or be secured
by other means.
A metallic contact arm D, shown in Figs. 3 & 4 passes round and is secured
to a block of insulating material E, and is pivotted at P, through its back end
between the pillars B2 & B3, the front ends of each arm, may be divided longi-
tudinally to enable it to expand and contract.
Two contact pieces F¹ & F2, are secured to the base, being divided by the
pillar B as shown, they are provided with terminals G1 G2, to receive the ends
of the line wires, and with slots J & J2, to receive the divided ends of the con-
tact arm D, when electrical contact is required.
These slots may be made elastic or expansible so as to grip the ends of the
arm D when forced into them to ensure perfect contact.
It will thus be seen that the contact arm makes electrical contact upon four
surfaces.
The contact arm moves upon its pivot P, and a coiled or other spring S, assists
in throwing off the contact when breaking circuit.
The switch handle or knob K, which I prefer to be similar to that known as
the "tumler" knob is carried by a ring of any suitable shape mounted upon
and secured to the three pillars B, it is pivotted to the ring, and its lower end
carries a small roller R, which rests upon the block E. When the knob is moved
the roller depresses the front end of the arm causing the ends to enter the
slots J of the contact pieces F¹ & F2, making contact and completing the circuit.
When the knob K is moved in the opposite direction the roller comes in contact
with the heel piece E3 of the block E, and the spring S, assists in raising and
holding up the arm out of contact.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1-An electric switch constructed as herein before described and shown in the
drawings.
2 In an electrical switch, a pivotted contact arm D constructed and operating,
in combination with the contact pieces, F1 F³, substantially as herein before
described and shown.
way of August 10.
ROBT. F. DRURY,
Agent for Applicant, Bank Buildings, George Street, Sheffield.