Improvements in Switches used for Electrical Purposes.
Year: 1889

page_text: Date of Application, 17th June, 1889
Complete Specification Left, 17th Mar., 1890-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Switches used for Electrical Purposes.
FREDERICK BAUMGART NICHOLSON of 7 Westminster Chambers, Victoria Street,
London S.W. Engineer do hereby declare the nature of this invention to be as
follows:
_:
The object of this invention is to produce a reliable, simple & cheaply constructed
switch and for this purpose I use a centre contact piece, turned taper & working in
suitably constructed contact pieces after the manner of a gas or water tap, & so
arranged that when the centre contact piece or bar is in one position that the metallic
or electric circuit is complete or in another position it is broken. The whole will
be understood to form a taper or plug held down or in position by a suitable spring or
other convenient means & capable of being turned by a handle or key.
A spring or springs may also be employed to keep the switch in any desirable
position or to give a tendency to keep in any desirable. position.
As an alternative plan I may use a cylindrical plug or tube working in contact
blocks having portions cut away in such manner that when in one position the
openings are opposite the contact blocks & the circuit or connection is therefore
incomplete and when turned in another position the metal between these intervals
recesses or cut away portions joins up the contact blocks & completes the circuit. The
tube being continuous in other parts holds the whole together & admits of a certain
amount of spring. A handle or insulating plug, or core may be passed through the
tube if considered desirable.
1
Dated this Fourteenth day of June 1889.
FREDERICK BAUMGART NICHOLSON.
COMPLETE SPECIFICATION.
Improvements in Switches used for Electrical Purposes.
I, FREDERICK BAUMGART NICHOLSON of 7, Westminster Chambers Victoria
Street, S.W. Engineer 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 :-
The object of this invention is to produce a reliable simple & cheaply constructed switch
and for this purpose (see drawings appended) I use a centre contact piece (A in
figure 1) made taper & working in suitably constructed contact pieces (B. fig. 1)
after the manner of a gas or water cock & so arranged that when the centre contact
piece or bar is in one position, the metallic or electric circuit is complete or in
another it is broken.
Fig. 1. is a section through X Y in Fig. 2. & the extension piece P may con-
veniently be used in connection with springs so as to keep the contact pieces in their
proper position in the usual manner.
In figure 2. C is formed of insulating material & the plug having diametrically
opposite recesses D. when it is turned in the position shown dotted causes the circuit
to be broken; if desirable C may be dispensed with and the recesses D filled with
insulating material turned to the same taper as the metal. A spring E or an elastic
washer may be used to keep the plug well on its seat. The whole will be understood
to form a taper or plug held down by a suitable spring washer or the like & capable
of being turned by a handle or key. A spring or springs may also be employed to
keep the switch in any desired position as explained with reference to P Fig. 1.

page_text: In figure 3 is illustrated a double pole switch made on the same plan in which
A & A B & B contact blocks & C. insulating material. The switch is shewn with
the circuit complete & when turned off the pieces A take the postion shewn dotted.
As an alternative plan I may use a cylindrical plug or tube working in contact
blocks having portions cut away in such manner that when in one position these
openings are opposite the contact blocks & the circuit or connections are therefore
incomplete & when turned in another position the metal between these intervals, recesses
or cut away portions joins up the contact blocks & completes the circuit. The tube
being continuous in other parts holds the whole together & admits of a certain amount
of spring. A handle or insulating core may be passed through the tube if considered
desirable.
This is illustrated in fig. 4 which shews the contact blocks B in section & the
tube or plug A in position & in plan Fig. 5. B is the contact block, A. the plug
Cinsulating material & the whole forms a horizontal section through W. Z.
Having now particularly described & ascertained the nature of my said Inven
tion & in what manner the same is to be performed I declare that what I
claim is
1st. The construction or combination & arrangements of the parts of a switch
substantially as & for the advantages herein described in reference to & shewn on the
accompanying Drawings.
2nd. The constructing of switches with the contacts tapered & so arranged that by
horizontal movement or rotation of either the central portion or the contact blocks,
the circuit shall be made or broken, substantially as & for the advantages herein
described in reference to & shewn on the accompanying drawings.
Dated this Fourteenth day of March 1890.
FREDERICK BAUMGART NICHOLSON.