Improvements in Electrical Switches.
Year: 1889

page_text: Date of Application, 7th Nov., 1889
Complete Specification Left, 7th June. 1890-Accepted, 12th July, 1890)
PROVISIONAL SPECIFICATION.
Improvements in Electrical Switches.
We FREDERICK LAWRENCE RAWSON of No. 11 Queen Victoria Street in the City
of London Electrical Engineer & WILLIAM WHITE of the same address Electrical
Engineer do hereby declare the nature of this invention to be as follows:-
Up to the present, there has been a difficulty in the use of switches where water or
inflammable gases are prevalent & our invention is to obviate this difficulty.
To do this, we enclose an electrical switch of any suitable form in a case of inetal
or other watertight material having stuffing boxes in its sides through which pass the
insulated conductors to the switch terminals. The top of the case is conveniently
formed as a cover which screws on to the lower part with a face and groove for
packing to render the joint water or gas tight; in the centre of this cover is a
stuffing box through which passes the handle spindle. This handle spindle has the
handle attached to it outside the cover stuffing box & inside it is formed so as to
engage with the switch contact arm through an insulating piece when the cover is in
place; but this coupling is free and is arranged so that the cover with the handle
spindle and handle is quite free to be taken off without interfering with the switch
contact arm.
Our invention forms a perfectly water & gas tight switch which is actuated by a
haudle on the outside in the usual way.
COMPLETE SPECIFICATION.
Improvements in Electrical Switches.
We FREDERICK LAWRENCE RAWSON, Electrical Engineer, of No. 88, Queen
Victoria Street, in the City of London, and WILLIAM WHITE, Electrical Engineer, of
58, Bread Street, in the City of London, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
Up to the present there has been a difficulty in the use of switches where water or
inflammable gases are prevalent, and our invention is to obviate this difficulty.
To do this we enclose an electrical switch of any suitable form in a case of
metal or other watertight material having stuffing boxes in its sides through which
pass the insulatated conductors to the switch terminals. The top of the case is con-
veniently formed as a cover which screws on to the lower part with a face and
groove for packing to render the joint gas aud water tight, in the centre of this
cover is a stuffing box through which passes the handle spindle. This handle
spindle has the handle attached to it outside the cover stuffing box and inside it
is formed so as to engage with the switch contact arm through an insulating piece
when the cover is in place, but this coupling is free and is arranged so that the
cover with the handle spindle and handle is quite free to be taken off without
interfering with the switch contact arm. Our invention forms a perfectly water
and gas tight switch which is actuated by a handle on the outside in the usual
way.
Reference to the enclosed drawings shows in Fig. 1 a vertical section and in
Fig. 2 a plan of an instrument constructed in accordance with this invention, the
case A being of metal or other watertight material and having stuffing boxes B
037

page_text: through which the insulated conductors C pass to switch terminals D. The cover
which is also watertight screws on to the lower part and has a face with groove E
for packing as shown and the handle spindle passes through the stuffing box F,
and engages with the switch contact arm through insulating piece G as shown and
is free to be removed with the cover.
Having now particularly described the nature of our invention, and in what
manner the same is to be performed, we declare that what we claim is :—
The construction of a watertight or gastigat switch substantially as described.
Dated this 7th day of June 1890.
F. L. RAWSON.
WM. WHITE.